Wales–Westminster Constitutional Development

Working analytical paper. Prepared for discussion and circulation, May 2026.

Executive summary

This paper examines Westminster-side constitutional development relating to Wales during the 2026-2030 Senedd term. It does not argue for a single constitutional endpoint. Instead, it considers where the present devolution settlement creates problems of institutional coherence, administrative functionality, accountability, intergovernmental friction, and constitutional asymmetry.

The central argument is that many current Wales-Westminster pressures arise where constitutional responsibility, political accountability, administrative authority, and institutional capacity no longer align cleanly together. In some areas, reform would serve both Welsh and UK Government interests by reducing friction, clarifying responsibility, or transferring operational responsibility closer to the institution already bearing political accountability. In other areas, the Welsh-interest case is stronger than the mutual-benefit case. In a smaller number of areas, particularly constitutional-pathway questions, the asymmetry between Welsh institutional development and UK Government interests is direct and should be acknowledged rather than obscured.

The strongest mutual-benefit cases concern intergovernmental relations reform, Sewel convention legislation, fiscal framework functionality, and Crown Estate devolution. These reforms would improve predictability, reduce avoidable constitutional conflict, and align responsibility more coherently within the existing United Kingdom framework. Crown Estate devolution is especially significant because the Scottish settlement provides an operationally settled precedent.

Justice and policing devolution, broadcasting reform, and rail services devolution present more complex cases. Each has a substantial Welsh-interest argument rooted in accountability, institutional coherence, and policy alignment. Each also presents implementation questions and areas of UK Government resistance. The Independent Commission’s preference for phased approaches in justice and broadcasting is therefore analytically important.

Plaid Cymru’s manifesto-derived constitutional positions extend the same territory into fiscal reform, needs-based funding, tax devolution, consequential funding, and Welsh external representation. These positions vary in strength and tractability, but they engage the same underlying questions of devolved functionality and intergovernmental friction.

Independence-related Westminster asks differ structurally from the rest of the paper. The administrative cost-transfer argument does not apply, and the mutual-benefit case is weak. The Welsh-interest case rests instead on democratic pathway clarity and the value of serious institutional analysis. The asymmetry with UK Government’s Union-preservation interest is real.

The paper concludes that Westminster-side constitutional development is unlikely to proceed as a single comprehensive settlement. It is more likely to involve cumulative institutional adjustment across different fields. The practical question is whether the constitutional structures surrounding Welsh governance remain capable of adapting coherently as Welsh democratic institutions continue to develop.

Section 1: Strategic frame

This paper examines Westminster-side constitutional development relating to Wales during the 2026-2030 Senedd term. Its focus is not the internal operation of Welsh institutions themselves, but the constitutional and intergovernmental structures through which Welsh institutions interact with Westminster, HM Treasury, UK-wide governance systems, and the wider territorial constitution of the United Kingdom.

It therefore operates as a companion paper to A Framework for Welsh Constitutional Development: Strategic Priorities for the 2026-2030 Senedd Term (May 2026), which addresses Welsh-side institutional capability development. The distinction matters analytically because constitutional functionality within devolved systems depends not only upon the capacity of devolved institutions themselves, but also upon how responsibilities, resources, accountability, and authority are distributed between devolved and central government.

The paper draws substantially upon the work of the Independent Commission on the Constitutional Future of Wales together with related constitutional analysis, fiscal review work, intergovernmental developments, and Plaid Cymru’s 2026 manifesto-derived constitutional positions. It does not assume that all constitutional reforms operate under identical political conditions or possess identical forms of constitutional justification. Some reforms concern administrative coherence and accountability within the existing devolution settlement. Others involve more substantial constitutional asymmetry where Welsh institutional development and UK Government constitutional interests diverge more directly.

The paper therefore approaches constitutional development primarily through institutional coherence, administrative functionality, intergovernmental friction, constitutional asymmetry, and governance consequence. Its purpose is not to advocate a single constitutional endpoint as a prerequisite for engagement with the reforms discussed within it. Many of the questions examined here can be approached within the existing United Kingdom settlement regardless of wider disagreement concerning Wales’s long-term constitutional future. Others cannot. Part of the analytical purpose of the paper is to distinguish clearly between those categories rather than obscuring the difference between them.

The central argument running throughout the paper is therefore limited but important: as devolution continues to evolve, pressures increasingly emerge where constitutional responsibility, political accountability, administrative authority, and institutional capacity no longer align cleanly together. The practical significance of many Westminster-side reforms lies not primarily in constitutional symbolism, but in whether the wider territorial constitution of the United Kingdom remains capable of operating coherently under conditions of continuing Welsh institutional development.

Section 2: The Independent Commission’s Westminster-side analysis

The Independent Commission on the Constitutional Future of Wales examined the future constitutional position of Wales through a broader and more structurally analytical framework than earlier Welsh constitutional commissions. Its significance lies not only in the individual recommendations it produced, but in the way it reframed Welsh constitutional discussion itself. The Commission treated constitutional development not simply as a question of national preference or institutional aspiration, but as a question of whether the constitutional structures governing Wales remained operationally coherent as devolution evolved.

Much of the constitutional pressure examined by the Commission did not arise from a single constitutional crisis or isolated policy dispute. It arose cumulatively through the practical operation of the devolution settlement itself. Welsh Government acquired increasing responsibility across major domestic policy areas while aspects of fiscal management, justice administration, infrastructure governance, broadcasting authority, constitutional process, and intergovernmental machinery remained partially reserved or structurally fragmented. The Commission’s analysis therefore focused repeatedly on questions of alignment: whether institutional responsibility, political accountability, administrative authority, and legal competence continued to operate coherently together as the settlement developed.

The result was a framework in which different categories of reform could be distinguished analytically rather than treated as a single constitutional package. Some reforms possess a relatively strong mutual-benefit case because they reduce friction, improve accountability, or align institutional responsibility more coherently with functions already substantially exercised within Wales. Intergovernmental relations reform, fiscal functionality, Crown Estate devolution, and aspects of rail accountability largely operate within this category. Others rest more heavily upon Welsh institutional interest while still producing identifiable UK governance advantages, including parts of justice and broadcasting reform. Others again involve substantial constitutional asymmetry where Welsh institutional development and UK Government constitutional interests diverge directly, particularly surrounding constitutional-pathway questions.

The Commission further differed from earlier constitutional exercises in the breadth of its comparative framing. Scottish and Northern Irish arrangements repeatedly functioned within the report not simply as political comparisons but as evidence that alternative constitutional structures could operate stably within the wider UK framework. This mattered analytically because it shifted several Welsh constitutional questions away from theoretical possibility toward practical consistency. The significance of the Scottish Crown Estate example, for instance, is less that devolution occurred than that the arrangement is now operationally settled within the wider constitutional system.

The report also reflected a growing tension within the territorial constitution itself: devolution has expanded incrementally over several decades, but the wider constitutional architecture surrounding it has often evolved more slowly and less coherently. This creates pressures which are institutional as much as ideological. Questions surrounding justice, rail governance, fiscal management, broadcasting authority, and intergovernmental machinery increasingly arise because devolved and reserved functions interact continuously in practice while remaining institutionally divided. The Commission’s analysis therefore repeatedly returns to the practical consequences of partial institutional separation operating over long periods of constitutional evolution.

The Commission was also notable for the degree to which it separated constitutional analysis from constitutional endpoint advocacy. Its final report examined strengthened devolution, federal approaches, and independence as constitutional futures without institutionally endorsing one outcome over the others. This neutrality mattered because it allowed the Commission to examine constitutional mechanics, institutional viability, and governance consequences without requiring all recommendations to point toward a single constitutional destination.

That analytical neutrality also strengthens the practical utility of many of the Commission’s recommendations. A substantial proportion of the reforms examined in this paper do not depend upon agreement regarding Wales’s ultimate constitutional future. Intergovernmental reform, fiscal functionality, Crown Estate devolution, rail accountability, and aspects of justice or broadcasting reform can all be engaged as questions concerning the operation of the present settlement rather than as implicit positions on independence itself.

The Westminster-side issues examined throughout this paper therefore span several distinct constitutional categories rather than a single reform programme. Recommendations concerning intergovernmental relations, Sewel codification, fiscal functionality, Crown Estate devolution, rail governance, broadcasting structures, justice, democratic arrangements, and constitutional-pathway questions each operate under materially different political and institutional conditions. The significance of the Commission’s framework lies partly in allowing those differences to be analysed explicitly rather than collapsed into a single constitutional binary.

At the same time, the Commission did not avoid constitutional asymmetry where it existed. In several areas, particularly surrounding constitutional-pathway questions, the report implicitly recognised that Welsh institutional interests and UK Government constitutional interests may not align. The Commission’s contribution is therefore not the elimination of constitutional disagreement, but the provision of a more structured analytical framework through which such disagreement can be examined.

This paper adopts that same broad approach. Its purpose is not to argue that every constitutional reform possesses equal political tractability or equal mutual benefit. Nor does it assume that all reforms examined here are equally likely to occur within the 2026-2030 Senedd term. Its purpose is narrower and more analytical: to examine the Westminster-side constitutional questions identified by the Commission within the evolving territorial constitution of the United Kingdom.

Section 3: Intergovernmental relations reform (Commission Recommendation 4)

Intergovernmental relations are the constitutional machinery through which the UK Government and the devolved governments manage shared or overlapping responsibilities. In practice, that machinery has often been too informal, too dependent on ministerial goodwill, and too weakly protected against unilateral action from the centre. This creates costs for Wales, but it also creates costs for the UK Government. Poor intergovernmental machinery does not merely frustrate devolved administrations; it produces recurring disputes, legal uncertainty, political damage, and repeated constitutional friction. Recent intergovernmental court cases, repeated Sewel disputes, and the controversies surrounding the United Kingdom Internal Market Act 2020 illustrate how visible and destabilising these costs have become.

The Independent Commission on the Constitutional Future of Wales therefore recommended that intergovernmental relations should be placed on a statutory footing. The significance of that recommendation is that it treats intergovernmental relations not as a matter of political courtesy, but as part of the operating system of the United Kingdom’s territorial constitution. The Commission’s recommendation does not prescribe a specific institutional design; it identifies the principle that intergovernmental machinery should be predictable, protected against unilateral disruption, and capable of resolving disputes through recognised channels rather than through ad hoc escalation.

The mutual benefit case is strong. Welsh Government gains predictability, earlier consultation, and a more secure route for raising Welsh interests where reserved policy affects devolved responsibilities. UK Government gains a more stable process for managing territorial issues before they become political crises. Statutory machinery could establish formal consultation timelines for legislation affecting devolved competencies, clearer channels for raising Welsh concerns about reserved matters, and recognised dispute-resolution processes. Friction is reduced because disagreement is handled through institutional routes rather than through public confrontation.

These structural costs apply across the devolution settlement. Scottish Government and Northern Ireland Executive face equivalent pressures from current intergovernmental arrangements, and the analytical case for statutory machinery is therefore four-nation rather than bilateral. This strengthens the case rather than weakening it: the dysfunction is structural across the UK’s territorial constitution, not specific to Wales.

This is not a complete answer to the constitutional pressures within the UK. It does not remove disagreement between governments, and it does not resolve the underlying question of where powers should sit. Its value is more practical than final: it makes disagreement more manageable, reduces avoidable constitutional damage, and gives all governments clearer expectations about process.

There is a real asymmetry. UK Government may prefer informal machinery because informality preserves discretion. But discretion has a cost when it produces repeated distrust. Statutory intergovernmental relations would trade some central flexibility for greater stability. That trade is not only a Welsh interest. It is a UK governance interest.

Section 4: Sewel convention legislation (Commission Recommendation 5)

The Sewel convention is one of the central operating conventions of the UK’s territorial constitution. In principle, the convention holds that UK Parliament will “not normally” legislate on devolved matters without the consent of the devolved legislatures. In practice, however, the convention remains political rather than statutory. It carries constitutional expectation but no legal force. This creates an unstable position in which devolved consent is recognised politically but can be overridden unilaterally where UK Government judges it necessary to do so.

That instability has become increasingly visible since 2018. Brexit-related legislation, the United Kingdom Internal Market Act 2020, the Subsidy Control Act 2022, and other measures proceeded despite explicit refusals of consent from devolved legislatures. These disputes imposed costs on both sides of the constitutional relationship. Welsh Government and Senedd faced direct limitations on the practical security of devolved competence. UK Government incurred repeated political criticism, constitutional controversy, intergovernmental deterioration, and in some cases legal challenge. The cumulative effect has been to weaken confidence in the predictability of the devolution settlement itself.

The Independent Commission on the Constitutional Future of Wales therefore recommended that the Sewel convention should be placed on a statutory footing. The significance of this recommendation is not simply procedural. It reflects the Commission’s broader argument that devolution requires constitutional mechanisms capable of operating predictably across political cycles and changes of government. A convention dependent entirely on restraint and political discretion becomes increasingly fragile when territorial disagreement intensifies.

The mutual benefit case is strong, although not symmetrical. Welsh Government and Senedd gain greater protection for devolved competence and a more secure constitutional role within the legislative process. UK Government gains a more stable and predictable territorial framework in which constitutional disputes are less likely to escalate into recurring political crises. Codification would not remove disagreement between governments, but it would create clearer expectations around process, consultation, and constitutional legitimacy.

The friction-reduction case is particularly significant. Repeated disputes over devolved consent generate political costs beyond the immediate legislation in question. They create wider distrust between governments, encourage constitutional escalation, and increasingly shift political disagreement into questions about the legitimacy of the territorial settlement itself. A statutory Sewel framework would not eliminate those tensions, but it would provide recognised constitutional procedures through which they could be managed more consistently.

The issue is not unique to Wales. Scottish Parliament and Northern Ireland Assembly face equivalent constitutional vulnerability under the present convention-only arrangement. The analytical case for codification is therefore UK-wide rather than Wales-specific. The repeated controversies surrounding devolved consent since Brexit have illustrated that the present arrangements generate instability across the territorial constitution as a whole.

There is, however, a genuine asymmetry. UK Government derives practical value from the present flexibility of the Sewel convention. The ability to legislate unilaterally in moments of perceived national priority preserves parliamentary sovereignty in its broadest interpretation and protects UK Government discretion where constitutional conflict emerges. Statutory codification would place limits on that flexibility. The constitutional trade is therefore real: greater territorial predictability and reduced intergovernmental friction in exchange for narrower unilateral freedom of action by UK Government.

This does not resolve the wider constitutional tensions within the United Kingdom, nor does it settle disagreements about where authority should ultimately reside. Its value is more limited and more practical. It stabilises one part of the constitutional relationship, reduces avoidable territorial conflict, and strengthens the predictability of devolution as a functioning constitutional system rather than as a series of political understandings dependent on restraint alone.

Section 5: Financial management constraints (Commission Recommendation 6)

Welsh Government operates within a fiscal framework that provides substantial spending responsibility while limiting several of the financial management mechanisms normally associated with long-term institutional planning. These constraints include annual and aggregate capital borrowing limits, restrictions on Welsh Reserve access, and continued HM Treasury oversight over elements of devolved fiscal management. The result is a system in which Welsh Government exercises significant operational responsibility while retaining comparatively limited flexibility in how devolved resources are managed across economic cycles.

The Independent Commission on the Constitutional Future of Wales therefore recommended reform of the fiscal management constraints operating within the current settlement. The significance of this recommendation is narrower and more technical than broader constitutional debates around sovereignty or macroeconomic independence. The Commission’s concern was not with separating Welsh fiscal policy from UK macroeconomic structures, but with enabling Welsh Government to manage devolved responsibilities with a level of financial flexibility more consistent with the scale of those responsibilities.

The mutual benefit case is moderate to strong, although more administrative and technical than in the preceding sections. Welsh Government gains increased capacity to manage infrastructure investment, reserve allocation, and medium-term fiscal planning within devolved competence. UK Government and HM Treasury gain reduced administrative involvement in routine devolved fiscal management decisions, alongside reduced intergovernmental friction surrounding borrowing approvals, reserve access, and repeated fiscal framework negotiations.

The friction-reduction aspect is particularly important. Fiscal disputes between HM Treasury and devolved governments frequently become politically disproportionate to the sums involved because they engage broader questions of constitutional status, institutional trust, and perceived Treasury discretion. More clearly structured fiscal management rules would not eliminate disagreement over funding levels or fiscal priorities, but they would reduce recurring procedural disputes about the operation of the framework itself.

The Welsh-interest case is also substantial. Greater borrowing flexibility increases Welsh Government’s ability to support infrastructure investment over longer timelines, including transport, housing, and institutional capability development. More functional reserve arrangements improve the government’s ability to manage spending volatility and respond to cyclical pressure on devolved services. Counter-cyclical flexibility within devolved competence becomes more workable when reserve and borrowing mechanisms operate predictably rather than through constrained annual negotiation.

The Scottish fiscal framework provides an important comparative reference point. Scottish Government already operates with greater borrowing and reserve flexibility than Welsh Government under the present settlement. The analytical case for Welsh reform is therefore not primarily an argument for novel constitutional architecture, but for a level of devolved fiscal management capability more proportionate to existing devolved responsibilities.

There are, however, genuine areas of uncertainty and contestation. Different analysts working from similar evidence reach different conclusions regarding appropriate borrowing limits, reserve structures, and the extent of Treasury oversight compatible with UK-wide fiscal stability. HM Treasury derives value from maintaining centralised fiscal control across the United Kingdom, particularly where devolved decisions may carry wider fiscal implications. However, HM Treasury also bears genuine costs from the present arrangements: detailed oversight of routine Welsh fiscal management decisions consumes Treasury administrative capacity, generates recurring intergovernmental friction, and absorbs Treasury staff time that could be directed to broader fiscal management priorities. The retained-oversight question is therefore not simply whether HM Treasury preserves value through centralised control, but whether maintaining that control at current scale justifies the administrative cost it creates.

The distinction between devolved fiscal management and macroeconomic sovereignty therefore matters. The reforms discussed in this section concern Welsh Government’s ability to manage devolved budget responsibilities more effectively within the United Kingdom’s broader fiscal and monetary framework. They do not concern monetary policy, currency arrangements, UK-wide fiscal rules, or wider macroeconomic governance, all of which remain outside the scope of the Commission’s recommendation and outside the scope of this paper.

The practical value of reform is therefore institutional rather than transformational. A more functional fiscal framework would not resolve wider constitutional disagreements, nor would it remove disputes about overall funding levels between governments. Its value lies in reducing administrative friction, improving devolved fiscal functionality, and aligning Welsh Government financial management capacity more closely with the responsibilities the devolution settlement already assigns to it.

Section 6: Broadcasting voice and devolution (Commission Recommendation 7)

Broadcasting occupies an unusual position within the Welsh constitutional settlement. It is deeply connected to Welsh democratic life, cultural continuity, and the operation of Welsh public discourse, yet substantial broadcasting authority remains reserved to Westminster and administered through UK-wide institutions. The result is a mixed arrangement in which Welsh broadcasting contains significant Welsh-specific provision but comparatively limited Welsh policy control over the structures through which that provision operates.

The current settlement reflects this complexity. S4C operates through a funding and governance structure involving UK Government, the BBC, and S4C itself. BBC Wales provides substantial Welsh news and cultural output, but remains institutionally embedded within a UK-wide broadcaster operating under UK-level governance and licence fee arrangements. Commercial broadcasting in Wales similarly operates under UK regulatory structures through Ofcom, with Welsh Government holding little direct influence over wider broadcasting policy despite the constitutional and democratic significance of the sector within Wales.

The Independent Commission on the Constitutional Future of Wales therefore recommended strengthening the Welsh voice within broadcasting policy and considering further broadcasting devolution. The Commission’s wording here was notably cautious. It did not propose immediate wholesale broadcasting devolution. Instead, it identified the growing mismatch between the democratic significance of broadcasting within Wales and the relatively limited Welsh institutional role within broadcasting governance.

The mutual benefit case exists, although it is more moderate than in earlier sections. UK Government currently manages recurring Welsh-specific broadcasting disputes through ad hoc engagement and partial accommodation within UK-wide structures. Questions surrounding S4C funding, BBC Wales resourcing, Welsh-language provision, and Welsh content representation repeatedly generate intergovernmental tension and political controversy. More clearly defined Welsh broadcasting competence or formal Welsh participation within broadcasting governance could reduce some of this recurring friction by creating more stable institutional routes for addressing Welsh-specific broadcasting questions.

There is also an administrative simplification argument. Dedicated Welsh competence over specific broadcasting areas would reduce the need for repeated case-by-case negotiation between governments over matters which are substantially Welsh in their practical operation and effect. The present arrangement often produces overlapping responsibility without entirely clear accountability.

The Welsh-interest case, however, is stronger than the mutual benefit case. Broadcasting plays a central role in sustaining Welsh democratic discourse, particularly within a devolved political system where substantial areas of public policy are now decided in Cardiff rather than Westminster. The institutional structures through which Welsh citizens receive political information therefore carry constitutional significance distinct from cultural policy alone.

The Welsh-language dimension strengthens the argument further. Welsh-language broadcasting is not simply a cultural preference but part of the practical infrastructure supporting the continued operation of Welsh as a living public language. Long-term sustainability in this area depends not only on funding levels but on institutional alignment between language policy, cultural policy, and broadcasting governance.

There is also a broader constitutional consistency argument. Scotland operates with broadcasting institutional infrastructure that Wales lacks: a separate Channel 3 licensee in STV, BBC Alba as a distinct Scottish-language channel within BBC structures, and a broader broadcasting institutional landscape that reflects Scottish constitutional distinctiveness. The 2021 Senedd Culture, Welsh Language and Communications Committee inquiry into broadcasting devolution recommended further Welsh competence including a formal role in licence fee setting and direct responsibility for S4C. The present settlement therefore appears uneven both in cross-national comparison and in light of Welsh institutional consideration of its own broadcasting position.

The asymmetry in this section is nonetheless substantial. UK Government derives genuine value from maintaining a largely integrated UK broadcasting system. Shared broadcasting infrastructure, UK-wide regulatory coherence, and common public-service broadcasting frameworks all carry operational and political advantages from Westminster’s perspective. Broadcasting devolution would therefore involve not simply transferring powers but unwinding elements of an integrated institutional landscape that, despite recurring friction, has operated in broadly recognisable form for decades.

There are also genuine analytical uncertainties. Full broadcasting devolution remains contested even among those broadly supportive of further Welsh constitutional development. Questions regarding funding sustainability, market scale, regulatory capacity, and the interaction between Welsh and UK-wide broadcasting systems all remain open. For this reason, phased approaches are analytically more defensible than immediate wholesale transfer. Greater Welsh participation within broadcasting governance, stronger formal Welsh policy input, and clearer institutional voice may prove more practically achievable in the medium term than comprehensive broadcasting devolution itself.

The Commission’s own formulation reflects this caution. Its recommendation was to strengthen the Welsh voice and consider devolution, not to prescribe a final institutional settlement in advance of further analysis. The practical value of reform therefore lies less in constitutional symbolism than in aligning broadcasting governance more closely with the democratic, cultural, and linguistic realities of contemporary Wales.

Section 7: Crown Estate and energy (Commission Recommendation 8)

Energy policy and Crown Estate management currently operate through a partially misaligned constitutional structure in Wales. Welsh Government possesses significant responsibilities in relation to planning, environmental regulation, renewable energy deployment, and aspects of economic development connected to energy infrastructure. However, substantial control over the underlying marine assets and associated revenues remains reserved through the Crown Estate framework. The result is a system in which Welsh institutions are expected to manage many of the practical and political consequences of energy development without equivalent control over the resource base itself.

The Crown Estate in Wales is presently administered as part of the UK-wide Crown Estate structure, with revenues flowing primarily to the UK Consolidated Fund and Welsh Government receiving funding indirectly through wider fiscal arrangements rather than through direct resource ownership. This differs from the Scottish settlement established following the Scotland Act 2016, under which Crown Estate Scotland has operated as a devolved Scottish public corporation since April 2017.

The significance of the Scottish example is not that the devolution itself was politically uncontested. It was not. Its significance is that the arrangement is now operationally settled. The transfer has demonstrated that devolved Crown Estate management can function within the wider constitutional structure of the United Kingdom without creating continuing institutional instability. The precedent therefore shifts the Welsh discussion away from theoretical viability toward questions of constitutional consistency and practical implementation.

The Independent Commission on the Constitutional Future of Wales recommended Welsh Crown Estate devolution alongside greater coherence between Welsh energy responsibilities and the constitutional structures through which those responsibilities operate. Plaid Cymru’s 2026 manifesto commitments engage substantially the same territory.

The mutual benefit case is strong. Administrative responsibility for Welsh Crown Estate assets would transfer from the UK-wide Crown Estate structure to Welsh institutions, reducing the portfolio scope managed centrally by UK Government structures. At the same time, one of the most persistent areas of Welsh constitutional grievance would largely be removed from the intergovernmental agenda. The current Scotland-Wales asymmetry itself generates recurring political friction because similar constitutional circumstances produce materially different institutional arrangements.

There is also a broader coherence argument. Welsh Government already exercises substantial influence over the planning and regulatory environment affecting offshore wind, marine energy, ports, and associated infrastructure. Yet the revenue and ownership framework connected to those same resources remains structurally detached from Welsh policy responsibility. This separation creates recurring tensions around investment incentives, infrastructure planning, and long-term resource management.

A more coherent settlement would align resource administration more closely with policy responsibility. Welsh Government would possess not only planning obligations but a direct institutional stake (including revenue rights and asset stewardship responsibility) in the long-term development of Welsh marine assets. This is particularly significant given the scale of offshore renewable potential around the Welsh coastline and the increasing strategic importance of energy infrastructure within wider UK economic and security policy.

The Welsh-interest case is therefore substantial. Direct Welsh control over Crown Estate revenues generated within Wales would alter the present fiscal relationship surrounding marine resources. More importantly, it would establish clearer institutional responsibility for how Welsh marine assets are developed, managed, and integrated into wider Welsh economic strategy.

The asymmetry in this section is limited. UK Government has already accepted the principle of Crown Estate devolution within the United Kingdom through the Scottish settlement. Extending a substantially similar arrangement to Wales therefore does not require the creation of entirely new constitutional architecture. It requires the adaptation of an existing precedent to Welsh circumstances.

There are nonetheless practical questions requiring further work. The precise operational boundary between UK-wide energy strategy and devolved resource management would need careful definition. Cross-border energy infrastructure, national grid coordination, offshore licensing interaction, and revenue transition arrangements would all require negotiated settlement. But these are implementation questions rather than arguments against the principle itself.

For that reason, this is one of the clearest examples within the paper of constitutional reform functioning simultaneously as Welsh institutional development and UK constitutional stabilisation. The case rests not only on Welsh political preference but on demonstrated operational precedent, administrative coherence, and the reduction of recurring intergovernmental friction generated by the current asymmetrical settlement.

Section 8: Justice and policing devolution (Commission Recommendation 9)

Justice and policing occupy a structurally unusual position within the Welsh devolution settlement. Wales possesses devolved responsibility across substantial areas of social policy closely connected to justice outcomes, including health, education, housing, local government, social services, and aspects of community safety. Yet the core justice system within which many of those policies ultimately operate remains reserved to Westminster through the England-and-Wales jurisdiction. The result is a constitutional structure in which Welsh institutions are expected to manage many of the social conditions connected to justice while holding comparatively limited authority over the justice system itself.

This position is increasingly distinct within the wider United Kingdom. Scotland has operated through a separate legal jurisdiction since the 1707 Union settlement. Northern Ireland’s justice functions were devolved in 2010 under post-Good Friday constitutional arrangements, demonstrating that phased justice devolution can be implemented within the United Kingdom without major institutional disruption. Wales therefore remains the only UK nation without devolved justice structures despite the continuing expansion of distinctive Welsh law and devolved Welsh policy responsibilities.

The Independent Commission on the Constitutional Future of Wales recommended a phased approach to justice devolution, beginning with policing, probation, and youth justice before any wider consideration of full criminal justice devolution. The Commission took as its starting point the Thomas Commission’s 2019 report Justice in Wales for the People of Wales, examining whether the evidence still supported its earlier case for devolution and seeking evidence in support of the present settlement. It found that the evidence for change substantially outweighed the evidence for retaining current arrangements. Plaid Cymru’s 2026 manifesto commitments engage substantially similar territory.

The significance of the Commission’s approach is that it treats justice devolution less as a symbolic constitutional demand and more as a question of administrative coherence. Distinctive Welsh justice pressures already exist operationally. Welsh-language court provision, Welsh youth justice priorities, differing approaches to community sentencing, and the interaction between Welsh social policy and reserved justice structures all require ongoing adaptation within the current settlement. The Commission’s recommendation therefore reflects the growing tension between devolved Welsh policy divergence and a justice framework still largely administered through England-and-Wales structures.

The mutual benefit case exists, although it is more politically asymmetrical than in earlier sections. The cost-transfer mechanism is significant. Responsibility for Welsh policing structures, probation administration, youth justice systems, and associated operational costs would transfer increasingly toward Welsh institutions. UK Ministry of Justice portfolio scope correspondingly reduces. Welsh-specific operational questions presently managed within UK-wide systems would move closer to the institutions already responsible for many adjacent policy areas.

There is also a friction-reduction argument, supported by a structural observation the Commission itself makes. The present settlement repeatedly generates tension where Welsh policy priorities intersect with reserved justice administration. Questions surrounding Welsh-language provision, prison geography, policing accountability, community sentencing, and youth justice approaches frequently require negotiation across institutional boundaries that do not align cleanly with existing devolved responsibilities. The Commission identifies an underlying consequence of this arrangement: within an integrated England-and-Wales justice system primarily structured around the much larger English system, Wales will necessarily remain a relatively low priority for UK Government attention. This is presented in the Commission’s analysis not as Welsh grievance but as structural observation. More integrated Welsh responsibility could reduce some of this recurring friction by aligning justice administration more closely with devolved Welsh policy structures already operating in related areas.

The Welsh-interest case, however, is substantially stronger than the mutual benefit case. Distinctive Welsh legislation increasingly operates within devolved areas, yet interpretation and enforcement continue largely through institutions operating within a broader England-and-Wales framework. As Welsh law develops further, pressure for corresponding Welsh legal and judicial capacity is likely to increase regardless of wider constitutional preference.

The community-policy dimension is also important. Youth justice, rehabilitation, restorative justice, and community sentencing all interact heavily with devolved Welsh services. Greater institutional alignment between justice administration and devolved social policy could allow Welsh Government to develop more integrated approaches across areas already substantially interconnected in practice.

There is nonetheless a significant asymmetry. UK Government derives genuine value from maintaining the existing England-and-Wales jurisdiction. The present system preserves institutional continuity, maintains unified legal administration across England and Wales, and avoids the operational complexity associated with jurisdictional separation. England itself does not operate through a devolved justice structure distinct from Westminster authority, and resistance to Welsh justice devolution partly reflects the constitutional embeddedness of the shared England-and-Wales model rather than solely opposition to Welsh institutional development specifically.

There are also genuine analytical uncertainties. Fiscal implications remain contested. Different analyses reach different conclusions regarding transitional costs, long-term budgetary sustainability, court administration structures, and the financial effects of prison and probation transfer. The precise operational boundary between devolved Welsh justice administration and continuing England-and-Wales legal coordination would also require careful definition.

For that reason, the Commission’s phased approach matters analytically. Policing, probation, and youth justice are identified as the appropriate initial phase for principled rather than purely pragmatic reasons. These are the areas where Welsh distinctive provision is already most advanced, where the operational interaction with already-devolved services such as health, education, housing, and social services is most direct, and where the administrative disentanglement from the integrated England-and-Wales system is most tractable. Full criminal justice devolution is left to a longer timescale, agreed between governments, with full implementation likely to require a decade-scale transition. The practical case for reform therefore rests less on constitutional symbolism than on the growing mismatch between devolved Welsh governance in practice and justice structures that have remained comparatively static as the wider devolution settlement has evolved around them.

Section 9: Rail services devolution (Commission Recommendation 10)

Rail infrastructure and rail service management within Wales currently operate through a layered and partially fragmented constitutional structure. Transport for Wales, owned by Welsh Government, already manages substantial elements of Welsh rail service operation. However, wider rail infrastructure remains largely controlled through UK-wide structures including Network Rail, the Department for Transport, and the Office of Rail and Road. Cross-border services, infrastructure investment decisions, and wider strategic rail planning therefore continue to operate through overlapping institutional responsibilities divided between Cardiff and Westminster.

This creates a position in which Welsh Government possesses significant transport responsibilities without possessing full authority over one of the most strategically important parts of the transport system itself. The resulting institutional overlap has become increasingly visible in recent years, particularly surrounding infrastructure investment, electrification priorities, cross-border coordination, and disputes connected to the classification of HS2 as an England-and-Wales project for Barnett purposes.

The Independent Commission on the Constitutional Future of Wales examined this arrangement and reached one of its more direct conclusions across the recommendations as a whole. Having considered whether a shared-governance solution based on improved intergovernmental relations could address the structural problems, the Commission concluded that recent intergovernmental history made such a solution unlikely to produce a fair outcome. The Commission further concluded that the existing governance structure does not allow sufficient direct scrutiny of Transport for Wales, Network Rail, Welsh Ministers, or the Secretary of State for Transport by either Parliament or the Senedd, and that the arrangements are not clear to members of the public who wish to raise concerns about rail provision. Recommendation 10 therefore proposed full devolution of rail services in Wales, funded fairly, on the analytical ground that this would achieve better outcomes for citizens and better value for money for public investment. Plaid Cymru’s 2026 manifesto commitments similarly support further rail devolution alongside Network Rail Wales transfer and resolution of HS2 consequential disputes.

The significance of the Commission’s recommendation is not simply that rail powers would move from Westminster to Cardiff. It is that the current settlement already produces many of the operational characteristics of partial rail devolution without corresponding constitutional coherence. Welsh Government carries substantial political responsibility for rail performance within Wales despite infrastructure authority and major investment decisions remaining partially reserved.

The mutual benefit case is moderate rather than overwhelming. Administrative responsibility for Welsh rail infrastructure could transfer from UK-wide structures toward Welsh institutions, reducing the operational portfolio managed centrally through Network Rail and related UK transport bodies. More importantly, clearer constitutional responsibility may reduce recurring intergovernmental friction surrounding rail investment priorities, infrastructure delays, electrification decisions, and strategic transport planning.

There is also a broader coherence argument. Welsh Government already exercises devolved responsibility across bus policy, active travel, roads, local transport integration, and substantial elements of economic development linked to transport infrastructure. Rail therefore increasingly appears institutionally separate from policy areas with which it must operate practically as part of an integrated transport system. Greater rail responsibility would allow more direct alignment between rail planning and wider Welsh transport strategy.

The Welsh-interest case is stronger than the mutual benefit case. Welsh transport geography differs materially from much of England, particularly in relation to west-east infrastructure concentration, north-south connectivity limitations, rural service pressures, and the economic significance of cross-border commuting. Welsh-specific investment priorities therefore do not always align neatly with wider UK infrastructure priorities determined centrally through UK-wide transport structures.

The HS2 controversy intensified this wider constitutional tension but should remain analytically distinct from the rail devolution question itself. The dispute surrounding HS2 consequentials concerns Treasury classification, Barnett methodology, and fiscal redress. Rail devolution concerns the institutional structure through which rail services and infrastructure are governed within Wales. The two questions are politically connected because both engage Welsh dissatisfaction with the present settlement, but analytically they are separable. Rail devolution may remain constitutionally coherent regardless of how the HS2 consequential dispute is ultimately resolved.

There are nonetheless substantial operational complexities. Rail infrastructure does not operate neatly within territorial boundaries. Cross-border passenger services, freight movement, infrastructure maintenance, signalling systems, and wider network coordination all require continuing cooperation between Welsh and UK authorities regardless of formal constitutional arrangements. The Commission acknowledged this directly, proposing that devolution proceed through a programme of work agreed between governments rather than through abrupt institutional separation. The Northern Ireland Railways arrangements and Scottish ScotRail provide partial precedent for devolved rail structures operating within wider UK rail interaction.

The asymmetry in this section is real but less severe than in justice or independence-related questions. UK Government derives value from maintaining integrated rail infrastructure across England and Wales, particularly where major transport corridors operate across the border continuously. However, UK Government also bears recurring political and administrative costs from disputes generated by the present partially devolved arrangement.

There are also genuine analytical uncertainties. The financial sustainability of fully devolved rail infrastructure, the scale of transitional administrative requirements, and the precise operational relationship between Welsh rail bodies and UK-wide rail systems remain contested. The Commission was explicit that devolution would need to be based on a fair and transparent funding settlement, agreed by both governments and scrutinised by elected members of Parliament and the Senedd. The implementation work required to establish that settlement is substantial, but the Commission considered and rejected the alternative of retaining the current arrangements with improved intergovernmental relations, concluding that the structural problems were not amenable to that solution.

The practical argument for reform therefore rests less on constitutional symbolism than on the growing mismatch between Welsh transport responsibilities already exercised in practice and rail governance structures that continue to operate through partially reserved institutional arrangements.

Section 10: Plaid manifesto-derived constitutional positions on Westminster-side reform

Alongside the Independent Commission’s recommendations, Plaid Cymru’s 2026 manifesto advances a number of additional constitutional positions relating to Westminster-side reform. These positions sit adjacent to, rather than fully within, the Commission’s recommendation structure. They are therefore treated here as manifesto-derived constitutional positions: proposals originating from party-political commitments but analytically engageable on their own terms.

Several of these positions concern the operation of the fiscal settlement between Wales and Westminster. The most significant is the proposal to replace the Barnett formula with a needs-based funding model reflecting Welsh demographic structure, economic conditions, geographic pressures, and the relative cost of public service provision. This position builds upon arguments previously developed through the Holtham Commission and subsequent fiscal analysis questioning whether population-based allocation alone adequately reflects relative spending need across the United Kingdom. Holtham Commission analysis in 2009 provided the analytical foundation for the Welsh block grant floor, later set at 115 per cent of comparable English spending, giving the needs-based question deep Welsh institutional roots across administrations of different political composition.

The mutual benefit case here is partial. A more transparent and analytically grounded funding methodology could reduce recurring disputes between devolved governments and HM Treasury over comparative funding fairness. More stable agreement regarding allocation principles may also reduce the cyclical political tension which regularly accompanies fiscal settlements and spending reviews. However, any movement toward needs-based redistribution also creates redistributive consequences elsewhere within the United Kingdom, and disagreement regarding methodology is unavoidable because “need” itself is not a politically neutral category. Different weighting models produce materially different outcomes.

The Welsh-interest case is correspondingly stronger than the UK mutual benefit case. Wales possesses demographic, geographic, health, and economic characteristics which frequently generate higher relative public service pressures than population allocation alone captures. The argument for reform therefore rests substantially on the claim that the present funding architecture does not fully reflect the actual cost structure of devolved governance within Wales.

Plaid’s manifesto-derived fiscal positions also include proposals for expanded Welsh borrowing powers, increased capital debt limits, more flexible Welsh Reserve arrangements, and further devolved tax competence including the devolution of Vacant Land Tax and wider consideration of made-in-Wales income tax structures. These positions overlap partially with the Commission’s concerns regarding fiscal management functionality, although they extend further into questions of devolved revenue generation and tax-policy autonomy.

The mutual benefit case here varies by proposal. Increased borrowing flexibility and reserve reform retain a relatively strong administrative and friction-reduction logic similar to that identified in Section 5. More devolved tax competence carries a more limited mutual benefit case, although it may reduce the need for repeated Treasury involvement in policy areas substantially Welsh in operational effect. The Welsh-interest argument is again stronger: greater fiscal flexibility and partial tax-policy control allow closer alignment between devolved economic priorities and the fiscal mechanisms through which those priorities are pursued.

The Vacant Land Tax case illustrates the practical operation of current arrangements. The Welsh Government proposed this tax to HM Treasury as the initial item in a programme of new Welsh taxes, and the Commission found that Treasury scrutiny had remained incomplete after four years, concluding that this delay appeared intended to act as a block on innovation rather than as substantive consideration. The income tax bands position raises a different analytical question. Scottish Government already exercises broader income tax band variation than Welsh Government, and the Commission identifies no principled case for this asymmetric treatment. However, Welsh Government has not used its existing income tax variation powers, reflecting concerns about tax flight given the inter-connectedness of Welsh and English economies. The case for additional tax powers is therefore well-grounded constitutionally, but the question of whether such powers would be substantively exercised in practice remains open.

The manifesto also engages continuing disputes surrounding consequential funding, particularly the treatment of HS2 as an England-and-Wales project for Barnett purposes. This question sits partially within fiscal administration and partially within wider constitutional trust. The dispute is not solely about the specific sums involved; it concerns whether Welsh infrastructure interests are treated symmetrically within UK funding frameworks. The Commission cited the HS2 dispute together with the 2012 London Olympics dispute as the two principal recent examples of intergovernmental disagreement arising from Treasury geographic-impact decisions, noting that significant disputes of this kind have been comparatively rare even where individual instances generate substantial controversy. The mutual benefit case for reform is therefore limited but not absent. More transparent consequential methodology could reduce recurring intergovernmental disputes and lessen the political friction generated by contested Treasury classifications. However, UK Government correspondingly loses a degree of interpretative flexibility within infrastructure funding decisions.

The manifesto additionally proposes stronger Welsh representation within UK external engagement structures, including enhanced Welsh participation within UK delegations and more formal Welsh external representation mechanisms. The practical significance of these proposals is narrower than some of the larger constitutional questions addressed elsewhere in this paper. However, they reflect the increasing interaction between devolved competencies and international policy areas such as trade, climate policy, higher education, energy investment, and cultural diplomacy.

The mutual benefit case in this area is modest but still present. UK negotiating positions affecting devolved competencies may operate more smoothly where devolved governments possess clearer routes for participation and consultation before positions are finalised. The Welsh-interest case again remains stronger than the wider UK governance argument, particularly where international agreements intersect directly with devolved policy implementation within Wales.

There are, however, genuine analytical uncertainties across all of these manifesto-derived positions. Needs-based fiscal allocation remains methodologically contested. Different approaches to measuring relative need produce different distributive outcomes across the United Kingdom. Tax devolution produces varying behavioural and administrative consequences depending on the specific tax involved. Infrastructure consequential disputes often depend upon Treasury classifications which are themselves open to competing interpretation. Even where the broad direction of reform appears analytically defensible, the precise institutional form remains contested.

For that reason, these positions are best understood not as settled constitutional conclusions but as extensions of the broader analytical territory opened by the Commission itself. They engage the same underlying themes recurring throughout this paper: administrative coherence, devolved functionality, intergovernmental friction, fiscal predictability, and the relationship between constitutional responsibility and institutional capacity. In some cases the mutual benefit case is strong; in others the Welsh-interest argument predominates. The value of engaging them analytically lies precisely in distinguishing clearly between those different categories rather than collapsing them into a single constitutional narrative.

Section 11: Senedd electoral reform (Commission Recommendation 3)

The Independent Commission on the Constitutional Future of Wales identified Senedd electoral reform as part of the wider question of institutional functionality within Welsh democracy. Recommendation 3 proposed a fully proportional electoral system, an expanded legislature, and reforms intended to strengthen the representative and scrutiny capacity of the Senedd. Unlike many of the Westminster-side recommendations examined elsewhere in this paper, however, much of this recommendation has already been substantially implemented through the Senedd Cymru (Members and Elections) Act 2024.

The 2026 Senedd election therefore took place under significantly revised electoral arrangements. The Senedd now operates through a larger chamber elected by a proportional system across multi-member constituencies. In practical terms, the principal constitutional question surrounding Recommendation 3 is no longer whether electoral reform should occur, but the extent to which Welsh democratic arrangements should remain dependent upon Westminster authority for their future development and amendment.

This creates a more limited but still analytically relevant Westminster-side question. The Senedd possesses competence over aspects of its own operation, much of which was provided through the Wales Act 2017, which gave the Senedd authority over the franchise for Senedd and local elections and over the name and size of the legislature. The 2024 Act built upon that competence in delivering the substantive electoral reform Recommendation 3 addressed. Ultimate constitutional authority over parts of the Welsh electoral framework, however, remains reserved within the wider UK constitutional structure. Future reforms relating to electoral arrangements, democratic safeguards, or candidate-selection mechanisms may therefore continue to require Westminster legislative involvement or operate within competence boundaries ultimately defined at UK level.

The mutual benefit case here is modest but still present. The direct administrative implications for UK Government are limited. However, continued Westminster involvement in detailed Welsh electoral administration creates constitutional friction disproportionate to the practical significance of the matters themselves. A more settled principle of Welsh democratic self-governance would reduce the need for recurring Westminster engagement with institutional questions whose practical operation is overwhelmingly Welsh in scope and effect. There is also a wider constitutional consistency consideration: devolved legislatures controlling their own electoral arrangements is the pattern already applying to the Scottish Parliament and Northern Ireland Assembly for most relevant matters, and extending this consistency to Wales would represent constitutional housekeeping rather than substantive transfer of UK Government function.

There is also a broader constitutional coherence argument. Devolved democratic institutions operating with limited authority over their own electoral arrangements create an incomplete form of institutional autonomy. The practical operation of Welsh democracy increasingly rests upon institutions making substantial decisions within devolved fields, yet the constitutional authority governing aspects of how that democratic system reproduces itself remains partially external to Wales. The Commission identified one practical consequence of this incompleteness in its observation that voters in Wales now participate in elections operating under materially different rules, with Senedd and local elections operating under Welsh Government policy on franchise and registration, and elections to the Westminster Parliament and to Police and Crime Commissioners operating under UK Government rules. The Commission described this asymmetry as confusing for voters but reflective of a defensible Welsh choice not to extend restrictive UK approaches to devolved elections.

The Welsh-interest case is therefore stronger than the mutual benefit case. The argument rests less upon any specific additional electoral reform and more upon the principle that democratic arrangements for devolved Welsh institutions should increasingly be matters for Welsh democratic determination. The issue is one of constitutional coherence rather than immediate institutional deficiency.

There is little asymmetry in this area. UK Government derives limited practical advantage from retaining continuing authority over detailed Welsh electoral arrangements, particularly now that major structural reform has already been enacted. The remaining question is therefore less politically contentious than many of the other constitutional issues examined in this paper.

The practical significance of this section is correspondingly narrower. Recommendation 3 has already been substantially actioned through existing legislation. What remains is the longer-term constitutional principle concerning the extent to which Welsh democratic institutions should possess continuing authority over their own electoral and institutional arrangements as the devolution settlement continues to evolve.

Section 12: Independence-related Westminster asks

Alongside its wider constitutional reform programme, Plaid Cymru’s 2026 manifesto advances several positions relating directly to the constitutional pathway question itself. These differ structurally from most of the reforms examined elsewhere in this paper. Recommendations concerning intergovernmental relations, fiscal management, justice, broadcasting, or rail governance operate within the existing devolution framework, even where they imply substantial institutional development. The independence-related positions instead concern the mechanism through which constitutional status beyond the current settlement could ultimately be determined.

The most significant of these positions is the proposal that authority to initiate a Welsh independence referendum should itself be devolved to the Senedd. Under the current constitutional structure, authority to legislate for a binding referendum concerning the constitutional status of Wales remains reserved to the UK Parliament. The position reflects the constitutional framework clarified through the 2022 Supreme Court judgment concerning the Scottish Parliament’s competence to legislate for an independence referendum without Westminster consent.

Plaid Cymru also supports the preparation of a future Welsh Government White Paper examining the institutional, economic, fiscal, and transitional implications of Welsh independence as one of the constitutional options identified by the Independent Commission on the Constitutional Future of Wales. The practical purpose of such a document would be analytical rather than determinative: to examine the viability, risks, institutional requirements, and transition questions associated with independence as a constitutional pathway.

The analytical structure of these positions differs significantly from earlier sections of this paper. The cost-transfer mechanism does not apply in any straightforward sense. Devolving authority over referendum initiation is not principally an administrative transfer comparable to rail infrastructure, justice administration, or fiscal management. It is a constitutional-pathway question concerning where authority ultimately resides regarding the future territorial structure of the United Kingdom itself.

The friction-reduction argument applies only partially and with important limits. The present constitutional arrangement has generated recurring political tension where devolved governments seek constitutional referenda which UK Government does not wish to authorise. The Scottish experience since 2014 illustrates this clearly. A more predictable constitutional framework governing referendum authorisation could reduce some of the recurring political conflict surrounding constitutional process itself, particularly where disagreement over procedure begins to eclipse disagreement over the underlying constitutional question.

However, the asymmetry in this section is substantial and should be stated directly. UK Government’s constitutional position is the preservation of the Union. A constitutional mechanism designed to facilitate lawful territorial separation does not align naturally with that objective. Unlike earlier sections where mutual administrative benefit, friction reduction, or institutional coherence provide meaningful shared incentives, the Welsh-interest case here operates against an area where UK Government possesses an explicit structural interest in maintaining the present constitutional order.

The Welsh-interest case is therefore primary rather than secondary. Supporters of devolved referendum authority argue that constitutional pathway clarity is itself democratically valuable: Welsh voters would know the constitutional mechanism through which future status questions could be determined, rather than such questions depending upon ad hoc UK Government agreement at moments of political pressure. The White Paper proposal similarly rests on the principle that constitutional debate should operate through publicly available institutional analysis rather than through abstraction, assumption, or rhetorical positioning alone.

There is also an analytical consistency argument. The Independent Commission explicitly examined independence as one of the three constitutional futures available to Wales while remaining institutionally neutral regarding which option Wales should ultimately choose. The existence of independence within the Commission’s analytical framework necessarily implies that questions surrounding constitutional process, institutional transition, and democratic authorisation are legitimate subjects for constitutional examination even where political disagreement regarding the endpoint remains profound.

There are nonetheless major practical and political constraints. UK Government presently shows little indication of supporting the devolution of referendum-authorisation powers, and the wider constitutional climate following the Scottish experience has generally moved Westminster toward greater caution rather than greater flexibility in this area. The practical implementation of such proposals within the 2026-2030 Senedd term therefore appears unlikely absent substantial changes in wider UK political conditions.

There are also genuine analytical uncertainties surrounding the White Paper proposal itself. The production of detailed constitutional transition analysis would require substantial institutional work across fiscal policy, monetary arrangements, legal transition, regulatory systems, citizenship, pensions, defence, international representation, trade, and border management. Many of these questions remain contested even in principle, and the production of a White Paper would not in itself resolve them. Its value would lie more narrowly in improving the quality of constitutional analysis available within Welsh public debate.

For that reason, this section differs fundamentally in character from most of the paper. Earlier sections frequently identify areas where Welsh institutional development and UK governance interests overlap. Here, the overlap is limited and partial. The constitutional asymmetry is real rather than rhetorical. The analytical value therefore lies not in attempting to force a mutual-benefit framework where it does not convincingly apply, but in documenting the distinction honestly.

Section 13: Sequencing and prioritisation

The constitutional reforms examined throughout this paper do not exist at a single level of political complexity or institutional tractability. Some operate through established precedent and comparatively limited constitutional disruption. Others require substantial institutional transition, sustained intergovernmental negotiation, or significant changes in wider UK political conditions. Any practical programme of Wales-Westminster constitutional development during the 2026-2030 Senedd term therefore requires sequencing rather than simultaneous pursuit across all areas.

Sequencing is not simply tactical. It reflects substantive differences in the degree of mutual benefit, the scale of institutional adjustment required, the level of UK Government political resistance likely to emerge, and the extent to which existing constitutional precedent already exists elsewhere within the United Kingdom.

The clearest early-phase reforms are those where mutual benefit is strongest and UK Government political cost is comparatively limited. Crown Estate devolution falls within this category because the Scottish settlement already provides an operationally settled precedent within the existing constitutional structure of the United Kingdom. Intergovernmental relations reform similarly possesses a strong four-nation rationale extending beyond Wales specifically. Fiscal framework reform also fits substantially within this category, particularly where the changes concern administrative functionality rather than wider macroeconomic questions.

The next category includes reforms where the mutual benefit case remains substantial but where UK Government political caution is likely to be greater. Sewel codification falls within this category because, although it may reduce long-term constitutional friction, it also limits unilateral Westminster flexibility in moments of territorial disagreement. Rail devolution similarly carries a coherent administrative and accountability case, but operational complexity and continuing cross-border coordination requirements make implementation more politically and institutionally demanding than Crown Estate transfer alone.

A further category consists of reforms where the Welsh-interest case is strong but where UK Government political resistance is likely to remain substantial despite the existence of identifiable structural benefits. Justice and policing devolution falls principally within this category. The administrative coherence argument is significant, and the cost-transfer and friction-reduction mechanisms are real. However, the constitutional embeddedness of the England-and-Wales jurisdiction means that institutional resistance is likely to remain stronger than in areas where clearer devolved precedent already exists.

Broadcasting reform occupies a similar but slightly more uncertain position. Greater Welsh institutional voice within broadcasting governance may prove politically achievable in the medium term, particularly where reforms remain incremental and governance-focused. Full broadcasting devolution would involve substantially greater institutional disentanglement from UK-wide broadcasting structures and therefore faces correspondingly higher political and operational barriers.

The final category consists of reforms where the constitutional asymmetry itself is central to the issue. Independence-related Westminster asks fall within this category because they concern the constitutional pathway through which the territorial structure of the United Kingdom itself could ultimately be altered. The mutual-benefit framework operating elsewhere in this paper applies only weakly in this area. Progress therefore depends less upon administrative logic or precedent and more upon wider political conditions within Wales and the United Kingdom over a longer timescale. The Welsh Government White Paper commitment on Welsh independence, although Welsh-side institutional work rather than a Westminster-side ask, sits within the same analytical territory: its value within the term is preparatory and analytical rather than directly productive of UK Government movement.

This sequencing logic also reflects an important cumulative effect. Earlier reforms establishing more stable intergovernmental machinery, greater constitutional predictability, and clearer devolved institutional responsibility may themselves alter the practical conditions within which later reforms are considered. Successful implementation of lower-friction reforms can increase institutional familiarity, reduce perceived constitutional risk, and establish working precedents for subsequent negotiation.

That does not mean constitutional development proceeds automatically or linearly. UK Government may reject elements of this sequencing framework entirely, regardless of the analytical strength of individual cases. Political bandwidth, electoral cycles, fiscal conditions, and wider UK constitutional pressures all affect what becomes practically achievable within a given period.

The significance of sequencing is therefore analytical rather than predictive. The purpose is not to forecast which reforms will occur during the 2026-2030 Senedd term, but to distinguish between reforms operating under materially different political and constitutional conditions. Some proposals are more tractable because they align Welsh institutional development with existing UK precedent and identifiable mutual benefit. Others remain politically difficult despite coherent administrative arguments. Others again concern constitutional questions where the underlying asymmetry is unlikely to be resolved within the present political settlement itself.

Section 14: Cross-party engagement strategy

The practical value of this paper depends partly on whether its analysis can be used beyond a single party-political setting. Plaid Cymru’s constitutional position gives it a clear interest in many of the reforms examined here, but Westminster-side constitutional change cannot be delivered by Plaid Cymru alone. Welsh representation at Westminster is necessarily distributed across several parties, and most Welsh MPs sit within UK-wide party structures. Any serious engagement with Westminster-side reform therefore requires analytical material capable of being used across party lines, even where constitutional preferences differ.

The strongest basis for cross-party engagement is not agreement on Wales’s final constitutional destination. It is agreement on specific institutional problems within the present settlement. Intergovernmental relations reform, fiscal framework functionality, Crown Estate devolution, rail accountability, and aspects of broadcasting voice can all be discussed as questions of Welsh governance effectiveness rather than as proxies for independence or unionism. That distinction matters because it allows Welsh MPs, Senedd Members, local government leaders, civic organisations, and policy specialists to engage with particular reforms without first agreeing on the whole constitutional question.

This framing is useful for that reason. It provides a language in which Welsh-interest arguments can be presented to Westminster audiences without requiring those audiences to accept a nationalist constitutional premise. Where reform reduces administrative friction, clarifies accountability, or transfers operational responsibility to the institution already bearing political responsibility, the case can be made in governance terms. That does not remove political disagreement, but it may widen the range of actors able to engage with the argument.

There are practical venues for this engagement. Welsh MPs across parties can use this material in debates, questions, committee work, and cross-party discussions. The Welsh Affairs Select Committee provides an obvious parliamentary route for examining intergovernmental relations, fiscal arrangements, rail accountability, Crown Estate devolution, and justice responsibilities. Cross-party Welsh parliamentary groups and issue-specific alliances may also be useful where an individual reform has wider Welsh support than the broader constitutional programme from which it originates.

Welsh Government engagement with UK Government remains the central institutional route. Analytical material of this kind can support that engagement by distinguishing between reforms where mutual benefit is strong, reforms where the Welsh-interest case is primary, and reforms where constitutional asymmetry is unavoidable. This distinction is important because not every proposal should be presented in the same way. Crown Estate devolution and intergovernmental relations reform can be advanced as comparatively low-friction structural improvements. Justice devolution requires a more cautious phased argument. Independence-related questions require honest recognition that UK Government’s structural interest is different.

The limits of cross-party engagement should also be clear. It cannot remove fundamental disagreement about Wales’s constitutional future. Nor can it make UK Government support reforms that it judges contrary to its political or constitutional interests. Its value is narrower: to make specific Welsh constitutional and institutional questions legible across party boundaries, to identify where shared Welsh interest exists, and to prevent analytically strong reforms being dismissed simply because they sit within a wider Plaid Cymru constitutional programme.

Section 15: Conclusion

The constitutional questions examined throughout this paper vary substantially in scale, political tractability, and constitutional consequence. Some concern relatively contained questions of administrative coherence and institutional accountability. Others engage deeper constitutional asymmetries within the territorial structure of the United Kingdom itself. Treating these questions as analytically identical obscures important differences in both the nature of the reforms proposed and the political conditions under which they operate.

The work of the Independent Commission on the Constitutional Future of Wales is significant partly because it provided a framework capable of distinguishing between these categories more clearly. Its analysis repeatedly identified pressures arising not solely from constitutional aspiration or political disagreement, but from the practical operation of a devolution settlement that has evolved incrementally over several decades while elements of the wider constitutional architecture surrounding it have remained comparatively static or fragmented.

Several of the reforms examined in this paper possess identifiable mutual-benefit characteristics extending beyond Welsh institutional interest alone. Intergovernmental relations reform, fiscal framework functionality, Crown Estate devolution, and aspects of rail governance and democratic accountability all engage questions of administrative coherence, accountability clarity, and intergovernmental stability across the wider territorial constitution. In these areas, constitutional development may function simultaneously as Welsh institutional strengthening and as UK governance stabilisation.

Other reforms operate under more asymmetrical conditions. Justice devolution, broadcasting restructuring, and constitutional-pathway questions engage areas where UK Government institutional interests and Welsh constitutional development pressures align less clearly. In those areas, constitutional disagreement is more substantive and less amenable to resolution through administrative logic alone.

This distinction matters because constitutional development within the United Kingdom is unlikely to proceed through a single comprehensive constitutional settlement. The pattern visible across the devolution era has instead been cumulative institutional adjustment, periodic structural tension, negotiated adaptation, and uneven constitutional evolution across different policy fields and territorial relationships. The pressures identified throughout this paper emerge largely within that wider process.

The paper also demonstrates that constitutional functionality and constitutional destination are not identical questions. Significant institutional pressures may exist within the present settlement regardless of wider disagreement concerning whether Wales should ultimately remain within a strengthened devolution framework, move toward federal structures, or pursue independence. A substantial proportion of the Westminster-side reforms examined here can therefore be engaged as questions concerning the operation and coherence of the present constitutional system itself rather than solely as proxies for wider constitutional preference.

At the same time, the limits of institutional reform should remain clear. Administrative coherence does not dissolve political disagreement. Improved intergovernmental machinery does not remove territorial tension. Fiscal reform does not settle wider debates concerning sovereignty or constitutional authority. Some asymmetries within the United Kingdom’s constitutional structure are administrative; others are fundamentally political.

The practical significance of the reforms examined throughout this paper therefore lies less in the promise of constitutional finality than in the management of constitutional evolution itself. As Welsh democratic institutions continue to develop, pressures surrounding accountability, authority, governance capacity, and constitutional coherence are likely to persist regardless of wider constitutional debate. The central analytical question is not whether constitutional development will continue, but whether the constitutional structures surrounding Welsh governance remain capable of adapting coherently as that development proceeds.

Sources and referenced materials

Primary documents

• Independent Commission on the Constitutional Future of Wales, Final Report (January 2024)
• Commission on Justice in Wales (Thomas Commission), Justice in Wales for the People of Wales (October 2019)
• Independent Commission on Funding and Finance for Wales (Holtham Commission), reports 2009-2010
• Plaid Cymru, For Wales: 2026 Manifesto

Legislation referenced

• Government of Wales Act 1998
• Government of Wales Act 2006
• Wales Act 2017
• Scotland Act 2016
• United Kingdom Internal Market Act 2020
• Subsidy Control Act 2022
• Senedd Cymru (Members and Elections) Act 2024

Constitutional jurisprudence

• Reference by the Lord Advocate (Scottish independence referendum), Supreme Court, 2022

Background analytical material

• Wales Governance Centre, Cardiff University: fiscal devolution and intergovernmental relations analysis
• Institute for Fiscal Studies: Welsh fiscal framework analysis
• Senedd Culture, Welsh Language and Communications Committee, inquiry into broadcasting in Wales (2021)

Document status: Circulation draft, May 2026. Five-stage review pass complete.

How this connects

This is the Westminster-facing companion to A Framework for Welsh Constitutional Development. Where the Framework concentrates on what Wales can build with its own devolved powers, this paper examines the reforms that need Westminster’s cooperation, taking each relevant recommendation of the Independent Commission on the Constitutional Future of Wales (2024) in turn. Read it after the Framework; the full list of works cited is in the Sources above.