Blog of the International Journal of Constitutional Law

Developments in UK Constitutional Law: The Year 2016 in Review

Editor’s Note: Today we publish the 2016 Report on United Kingdom constitutional law, which appears in the larger 44-country Global Review of Constitutional Law, now available here in a smaller file size for downloading and emailing.

–Stephen Tierney*    Asanga Welikala+    Tom Gerald Dalyǂ

I. Introduction

The idea of ‘union’ was the central constitutional focus for the United Kingdom in 2016. The nature of the United Kingdom (UK) as a multinational state was radically overhauled by the Scotland Act 2016 and by the bill that became the Wales Act 2017. But 2016 will surely be best remembered for the referendum held on membership of the European Union (EU) and the dramatic decision taken by the British people to leave a union that has exerted such an extensive influence over the British constitution since 1973.

In this report, we reflect upon these developments and the interactions between devolution and ‘Brexit’. In light of the radical changes to the internal territorial union and the UK’s external union with Europe, we can surely say that 2016 was a seminal moment in the development of the modern United Kingdom constitution to rank alongside 1885, 1911, 1922, and 1997.

II. The Constitution and the Court

The unentrenched nature of the British Constitution, the evanescent boundaries between ‘constitutional’ law and ordinary law (and between law and politics more widely), and the less central role for the courts in a system where Parliament is supreme marks the United Kingdom as an outlier in a world of increasingly detailed and judicially regulated constitutions.

The defining characteristic of the UK constitution is parliamentary supremacy, which means that the courts have traditionally taken a back seat in constitutional matters. This changed to some extent with the Human Rights Act 1998, which gave the courts more interpretive discretion without introducing the power to strike down statutes.[1] Membership of the European Union has proved difficult for the courts in terms of reconciling parliamentary supremacy with the self-declared supremacy of EU law.[2] But it is notable that the courts have been very careful not to overstep their proper constitutional position. This is evident when we look at devolution. The courts have taken a light touch to policing the boundaries of competence of the devolved territories–Scotland, Wales, and Northern Ireland–with few cases coming before the courts, and these rarely raising issues of major controversy.

Nonetheless, flexibility and pragmatism are appropriately viewed as the defining virtues of the British constitutional tradition.[3] In this context, constitutional change has taken place through ordinary legislation, supported by a network of prerogative power (the royal prerogative power was originally exercised by the reigning monarch, but is now generally exercised by Government ministers in the name of the Sovereign[4]), and constitutional conventions which are not legally enforceable. Since the courts have not been central players in constitutional change as they have elsewhere, it is therefore particularly notable that the major cases which emerged in the context of the Brexit referendum have focused entirely upon the issue of Parliament’s supremacy and its interaction with the devolution statutes, the prerogative power, and constitutional conventions.

III. Constitutional Controversies

The main controversy in 2016 was the Brexit referendum and its aftermath. But in this section we will also discuss changes to the devolution settlements for Scotland and Wales, which are also very significant but which have tended to be overlooked in light of the EU referendum.


The Conservative Party’s success in the 2015 general election required it to make good on its campaign pledge to hold a referendum on the UK’s continued membership of the EU,[5] and the referendum was duly held on 23 June 2016. The unexpected ‘Leave’ vote – by a slim margin of 52% to 48% – has led to the resignation of Prime Minister David Cameron and left the next Government, under Prime Minister Theresa May, charged with the complex task of achieving a divorce from the EU that complies with UK constitutional law, EU law, and wider commitments under international law (particularly as regards the Good Friday Agreement, a bilateral international treaty between the UK and Ireland in 1998, which, with the accompanying Northern Ireland Act 1998 passed by the UK Parliament, established a peace settlement in Northern Ireland).

The process of withdrawal from the EU is governed by Article 50 of the Treaty on European Union (TEU).[6] As the UK is the first state to seek to leave the EU, the precise requirements and procedure to be followed under Article 50 are unclear and have been the subject of much discussion at both the national and EU levels. The prospect of Brexit has also sparked renewed discussions of profound constitutional change within the UK, not only through an official request by the Scottish Government for the authority to hold a second independence referendum,[7] but also in calls for constitutional change for Northern Ireland.[8] Below, we will return to the litigation provoked by the June referendum.

Devolution Developments

Scotland Act 2016

The Scotland Act 2016 provides the Scottish Parliament with a set of new powers that will make it one of the most autonomous sub-state legislatures in the world. It considerably extends the powers already provided for in the Scotland Acts of 1998 and 2012. The Scottish Parliament acquires a range of additional competences in policy areas such as taxation, welfare, unemployment services, transport, energy efficiency, fuel poverty, and onshore oil and gas extraction. It is the provisions on taxation that have attracted the most attention. In light of the Scotland Act 2016, Scotland will acquire far more fiscal responsibility.[9] In particular, it has been given extensive powers in relation to income tax raised in Scotland which is important in symbolic as well as practical terms. This builds upon the more modest tax powers which were included in the 2012 Act, a number of which are still to be implemented.

The 2016 Act also changes the constitutional status of the Scottish Parliament, providing: ‘The Scottish Parliament and the Scottish Government are a permanent part of the United Kingdom’s constitutional arrangements’.[10] It is difficult to see what constitutional effect this might have, given the UK’s doctrine of parliamentary sovereignty,[11] but the very statement could be a steer to the courts to consider Scottish devolution now to be an entrenched arrangement at the level of constitutional principle.[12]

English Votes for English Laws (EVEL)

The Scotland Act was the culmination of the promise of more powers for the Scottish Parliament in light of the independence referendum in 2014, in which 45% of voters opted for independence. From this process what also emerged was resentment within England at how devolution continued to expand with no account of the constitutional position of England.

This resulted in a change to parliamentary procedure known as ‘English Votes for English Laws’ (EVEL). The system was introduced in 2015 through an amendment to the Standing Orders of the House of Commons.[13] It seeks to address the ‘West Lothian Question’.[14] This question refers to whether Westminster MPs from Northern Ireland, Scotland and Wales should be able to vote on matters that affect only England while MPs from England are unable to vote on matters that have been devolved to the devolved legislatures.

EVEL attempts a procedural solution within the law-making process of the UK Parliament, by giving a veto, respectively, to the whole House of Commons and to a Grand Committee of Welsh and English MPs. The Speaker is given a role in deciding which Bills or provisions of Bills fall within the ambit of the new procedure. In legislation affecting only England (or England and Wales), English (or English and Welsh) MPs are offered a vote, although the whole House of Commons retains a power to reject these votes. Conversely, English (or English or Welsh) MPs can also veto Bills over devolved matters affecting England (or England and Wales) that have been approved by the whole House.[15]

Reviews of the complex system in operation, while raising deep philosophical questions,[16] have broadly noted that it is too early to draw definitive conclusions about its strengths and weaknesses, although it will not be long before the internal territorial implications of withdrawing from the European Union will pose severe tests for EVEL.[17]

Wales Act 2017

The process of making major changes to the devolution settlement in Wales continued throughout 2016, culminating in the Wales Act 2017.[18] It introduces a reserved powers model of devolution for Wales.[19] In provisions similar to those in the Scotland Act 2016, it provides for the permanence of Welsh institutions of government, including through the requirement of a referendum for the abolition of the National Assembly. It recognises the convention (‘the Sewel convention’[20]) that the UK Parliament will not normally legislate in areas of devolved competence, even though it retains the legal power to do so (such a provision is also to be found in the Scotland Act 2016). It also devolves further legislative and executive powers over a range of competences to Wales, including over elections, onshore petroleum, road transport, ports, electricity generation, equal opportunities, marine conservation, and some other more specific powers.

Another noteworthy feature of the 2017 Act is the recognition of a distinctive body of Welsh law. Unlike Scotland and Northern Ireland, which have long had separate judicatures and bodies of law, Wales belongs to the single legal jurisdiction of England and Wales. The purpose of the new provision is to recognise the body of distinctive primary and secondary legislation enacted by the Welsh Assembly since the advent of devolution, which forms part of the laws of the jurisdiction of England and Wales, but which applies only to Wales.[21]

Constitutional innovations such as the provisions concerning permanence and consent, however, have to be understood in the context of the doctrine of parliamentary sovereignty, which continues to be the fundamental rule of the UK constitution.[22] This means that a future Parliament can legally change any existing legislation, including those of a constitutional character, through ordinary legislative procedure. Nevertheless, the fact that Parliament has given a commitment to the principle that the Scottish and Welsh institutions can no longer be abolished except through a referendum in each territory respectively seems to be a form of contingent entrenchment that reinforces the political limits, and arguably the legal limits, of the UK Parliament’s legislative capacity.

IV. Major Cases

The main focus in 2016 was upon significant litigation concerning Brexit. Two separate strands of litigation have addressed the issue of consent in the initial stage of the process of withdrawing from the EU, set out in Article 50 TEU: (i) two cases brought before the High Court in Northern Ireland concerned whether, under the existing devolution framework, the consent of the Northern Ireland Assembly was required to trigger the UK’s exit (with implications for the devolved nations more generally); and (ii) the Miller case before the High Court of England and Wales concerned whether authorisation was required from the UK Parliament to trigger Article 50. Both strands of litigation were joined for hearing before the Supreme Court in December 2016, which issued a judgment in January 2017.

The High Court of Northern Ireland decision in McCord’s Application

The judicial review applications considered in the McCord litigation advanced five main issues for the Court’s consideration.[23] First, it was argued that the executive prerogative in respect of foreign relations and treaty-making had been displaced by the Northern Ireland Act 1998, read together with the Belfast Agreement and British-Irish Agreement, which not only established the distinctive Northern Ireland (NI) power-sharing and human rights arrangements, but also did so on an irreplaceable assumption of continuing UK membership of the EU. In the applicants’ view, immediate changes would occur in these arrangements, including rights deriving from EU law, by even the initial step of a notification of withdrawal under Article 50 TEU. Since the prerogative cannot be used to change domestic law, the applicants contended that the UK Government needed prior parliamentary sanction in the form of an Act of Parliament to trigger Article 50.

The Court, however, was unable to find any legal provisions applicable to Northern Ireland that expressly or impliedly displaced the prerogative in respect of the UK’s relationship with the EU, even though the fact of EU membership was assumed at the time the 1998 Act and other Agreements were put in place. Moreover, the Court did not agree that the mere act of triggering Article 50 would affect any existing rights; although this may well happen in the future, albeit through legislation giving effect to the terms of the UK’s eventual withdrawal.[24]

If an Act of the UK Parliament was needed for triggering Article 50, the applicants argued, secondly, that by convention there needed to be a ‘Legislative Consent Motion’ passed by the NI Assembly before the UK Parliament could act. Given the High Court’s finding on the first issue that the UK Government has authority under the prerogative to act, this was perhaps superfluous. But it nevertheless considered the question whether triggering Article 50 would affect a devolved matter, and concluded it did not; that is, within the scheme of devolved (‘transferred’) or reserved (‘excepted’) matters under the 1998 Act, triggering Article 50 concerned relations with the EU institutions, which is an excepted or UK competence.[25]

The third argument averred that even if the prerogative was available to the UK Government, a number of public law restraints would apply to its exercise to ensure that the Government took all relevant considerations into account – including the unique constitutional arrangements of the NI within the UK and the need to uphold EU law so long as the UK remained a member-state – and that it would not give excessive consideration only to the referendum result. The Court questioned the justiciability of many of the contentions on this ground, concluding that triggering Article 50 would be a decision of high policy taken at the highest levels of the state, pursuant to a state-wide referendum, that would be inappropriate for judicial review.[26]

The last two of the applicants’ arguments also found no favour with the Court. Briefly, these were that the decision to trigger Article 50 would be in violation of the 1998 Act’s provisions requiring the Secretary of State for Northern Ireland to assess the measure’s impact on equal opportunities in NI; and that the Good Friday Agreement gives rise to a substantive legitimate expectation that the constitutional status of NI would not be altered without a referendum. The Court found that triggering Article 50 was not a matter for the NI Secretary but for the Prime Minister and other members of the UK Cabinet.[27] Similarly, it held that any referendum provision in the Good Friday Agreement was about NI remaining within the UK, rather than the UK’s relationship with the EU.[28] These matters were all appealed to the Supreme Court (see below).[29]

The High Court judgment in the Miller case

Parallel to the litigation in Northern Ireland, the applicants in R (Miller) v Secretary of State for Exiting the European Union argued that the UK Government’s plan to trigger the process of leaving the EU under Article 50 TEU through exercise of the royal prerogative power is unacceptable under UK constitutional law. They contended that the initiation of the process required statutory authorisation from Parliament on the basis that the prerogative has been displaced by the European Communities Act 1972, which was enacted to facilitate the UK’s entry into the European Economic Community in 1973.

At first instance, the High Court issued a judgment of 3 November 2016[30] holding that the triggering of Article 50 TEU does require the statutory authorisation of Parliament. The judgment was met with fury by the anti-EU press, including the Daily Mail’s now infamous front page decrying the High Court judges as ‘enemies of the people’.[31] The headline was widely criticised as failing to respect the independence of the judiciary and was the subject of over 1,000 complaints to the Independent Press Standards Organisation.[32]

The UK Government appealed the decision to the UK Supreme Court, which heard the case on 5-8 December 2016, joining it to the appeal against the High Court of Northern Ireland in the McCord case.

The Supreme Court judgment

On 24 January 2017, the Supreme Court handed down its decision in the joined appeals against the judgments in Miller and McCord.[33] In a joint majority decision of 8 judges (with 3 judges issuing separate dissents), the Supreme Court upheld both judgments.[34]

Regarding the matters raised in Miller, the Supreme Court upheld the judgment of the High Court requiring that Parliament must pass an act authorising the Government to notify the UK’s intention to withdraw from the EU under Article 50 TEU. The judgment, like the first instance judgment, was framed as an analysis of the constitutional relationship between the Parliament and the Executive, focused on detailed analysis of the nature of the royal prerogative power exercised by Government ministers.

The main question centred on two foundational rules: (i) the Executive cannot, through exercise of the royal prerogative, change domestic law;[35] and (ii) the making and unmaking of international treaties is a foreign relations matter that falls within the competence of the Executive. The Court considered that use of the prerogative power to vary the content of EU law (arising from new EU legislation) could not be equated to the ‘fundamental change in the constitutional arrangements of the UK’[36] occasioned by exit from the EU, that the absence of any express conferral of power to the executive to withdraw from the European Community (now Union) under the 1972 Act meant that such a power did not exist, and that individual rights enjoyed as a result of EU membership would be affected as soon as Article 50 was triggered.[37]

Regarding the devolution-specific arguments raised in McCord, the Court dismissed the appeal against the judgment of the High Court of Northern Ireland (as well as similar arguments advanced by the Scottish Government before the Supreme Court), by holding that the consent of the devolved legislatures is not required for the triggering of Article 50.

The Supreme Court’s analysis centred on the constitutional status of the ‘Sewel convention’ (that the UK Parliament would not normally legislate with regard to devolved matters except with the agreement of the devolved legislature), which is referred to expressly in the Scotland Act 2016. The Supreme Court, while recognising that the Sewel Convention can play a fundamental role in the constitutional framework concerning devolution, took the view that its enforcement was a political matter, reflecting the systemic tendency to avoid judicial resolution of matters ruled by convention. With regard to Northern Ireland specifically, the Supreme Court dismissed the additional argument that the consent of the people of Northern Ireland was required to take Northern Ireland out of the EU, based on Article 1 of the Northern Ireland Act 1998, which provides that Northern Ireland shall not cease to be a part of the UK without the consent of the people.[38]

The three dissenting judges (Lords Reed, Carnwath, and Hughes) took no issue with the majority’s decision on the devolution framework, but disagreed fundamentally with the majority on the requirement for parliamentary authorisation to trigger exit under Article 50 TEU. Lord Reed, for instance, stressed that the principle that the conduct of foreign relations is a matter for the Crown is “so fundamental” that it can be overridden solely by an express legislative provision or by necessary implication,[39] and considered that the 1972 Act in no way precluded the use of the prerogative power to trigger Article 50 TEU, given that the domestic effect accorded to EU law by Parliament in enacting the 1972 Act was ‘inherently conditional’ on the UK’s membership of the EU, the 1972 Act itself imposes no requirement of UK membership of the EU, and that the 1972 Act had not changed in any way the fundamental sources of domestic law or the principle of parliamentary sovereignty.[40]

The Supreme Court’s judgment was not met with the same level of vituperation as the High Court judgment, and was hailed (by some) as ‘the most significant constitutional judgment for a generation’ and ‘a triumph for Britain’s judicial system and the Supreme Court’.[41] The pro-Brexit media turned their attention to the potential derailing of Brexit in Parliament. Nevertheless, the Supreme Court’s centrality in resolving this constitutional dispute has brought virtually unprecedented scrutiny to an institution that does not have the power to strike down statutes.

V. Conclusion

The decision to leave the European Union will put great strain upon Parliament and Government as they seek to extricate the UK from over 40 years of EU membership and the tens of thousands of laws emanating from Brussels. It will also put great strain upon the territorial constitution, particularly as the Brexit decision has served to revitalise nationalism in both Northern Ireland and Scotland.

The courts played a role in the Miller case where they intervened to clarify the power of Parliament in relation to important prerogative powers and constitutional conventions. It is likely that they will continue to have influence as Brexit is achieved and as the new territorial statutes for Scotland and Wales take effect. But the main challenges ahead are political. The new devolution settlements for Scotland and Wales have brought with them a range of powers that are now shared with the central Government while Northern Ireland remains a very delicate situation where devolution is both volatile and fragile. The real task facing the UK constitution in the coming years is that of intergovernmental relations. The UK Government must seek to manage Brexit negotiations in a way that is attentive to the reality of the UK as a multinational state. Otherwise the process of leaving one union – the European Union – could serve to undermine fatally the UK’s own internal unions.

* Professor of Constitutional Theory, School of Law, University of Edinburgh; Director, Edinburgh Centre for Constitutional Law; Legal Adviser, House of Lords Constitution Committee. Email:

+ Lecturer in Public Law, School of Law, University of Edinburgh; Associate Director, Edinburgh Centre for Constitutional Law. Email:

ǂ MLS Fellow, Melbourne Law School; Associate Director for Research Engagement, Edinburgh Centre for Constitutional Law. Email:

[1] Human Rights Act 1998 ss 3-4.

[2] R (Factortame Ltd) v Secretary of State for Transport (No 2) [1991] 1 AC 603; (HS2 Action Alliance Ltd) v Secretary of State for Transport [2014] UKSC 3.

[3] See e.g. G Marshall, ‘The Constitution: Its Theory and Interpretation’ in V Bogdanor (ed.), The British Constitution in the Twentieth Century (Oxford University Press, 2003) 33.

[4] See generally T Poole, Reason of State: Law, Prerogative and Empire (Cambridge University Press, 2015).

[5] See The Conservative Party Manifesto 2015 72ff.

[6] A brief summary of the process is provided in T Lock and TG Daly, Legal Implications of Brexit and the British Bill of Rights (Edinburgh Law School and Bingham Centre for the Rule of Law) 20.

[7] The request was made by a letter from First Minister Nicola Sturgeon to Prime Minister Theresa May dated 31 March 2017, the text of which is available at See also S Tierney, ‘A Second Independence Referendum in Scotland: The Legal Issues’ U.K. Const. L. Blog (13 March 2017)

[8] See e.g. T Reidy, ‘Scottish Independence and a United Ireland: A Brexit Game of Gaelic Games?’ Irish Politics Forum (21 March 2017)

[9] House of Lords Constitution Committee, ‘Proposals for the devolution of further powers to Scotland’, 18 March, 2015, para 95.

[10] Scotland Act 2016, s.1.

[11] M Elliott, ‘The Draft Scotland Bill and the sovereignty of the UK Parliament’, Public Law for Everyone blog, 22 January 2015

[12] K Campbell, ‘The draft Scotland Bill and limits in constitutional statutes’ U.K. Const. L. Blog (30 January 2015)

[13] R Kelly, ‘English votes for English laws’, House of Commons Library Briefing Paper No. 7339, 2 December 2015:

[14] P Bowers, ‘The West Lothian Question’, House of Commons Library Standard Note SN/PC/2586, 18 January 2012:

[15] M Elliott and S Tierney, ‘House of Lords Constitution Committee Reports on ‘English Votes for English Laws’ U.K. Const. L. Blog (2 November 2016):

[16] See e.g. B Guastaferro, ‘Disowning Edmund Burke? The Constitutional Implications of EVEL on Political Representation’, U.K. Const. L. Blog (2 May 2016):

[17] House of Lords Constitution Committee, ‘English Votes for English Laws’, 6th Report of Session 2016-17, 2 November 2016, HL Paper 61:; UK Government, ‘Technical Review of the Standing Orders Related to English Votes for English Laws and the Procedures they Introduced’, March 2017, CM9430:

[18] For background, see Wales Governance Centre and The Constitution Unit, ‘Challenge and Opportunity: The Draft Wales Bill 2015’, February 2016:; A Cogbill, ‘The Wales Bill 2016: A Marked Improvement but there are Fundamental Questions Yet to be Resolved’, The Constitution Unit Blog, 26 July 2016:

[19] P Bowers, ‘Wales Bill 2016-17’, House of Commons Library Briefing Paper No. 07617, 13 June 2016:

[20] A Trench, ‘Legislative consent and the Sewel convention’, Devolution Matters Blog, March 2017:

[21] Ibid.

[22] Ibid.

[23] McCord’s (Raymond) Application [2016] NIQB 85:

[24] Ibid: [65] – [108].

[25] Ibid: [109] – [122]

[26] Ibid: [123] – [136]

[27] Ibid: [137] – [146]

[28] Ibid: [147] – [157]

[29] See also C Harvey, ‘Northern Ireland’s Transition and the Constitution of the UK’, U.K. Const. L. Blog (12 December 2016):

[30] [2016] EWHC 2768 (Admin).

[31] ‘Enemies of the people: Fury over  “out of touch” judges who have “declared war on democracy” by defying 17.4m Brexit voters and who could trigger constitutional crisis’ Daily Mail 4 November 2016

[32] ‘Daily Mail’s “Enemies of the People” front page receives more than 1,000 complaints to IPSO’ Independent 10 November 2016

[33] [2017] UKSC 5.

[34] A useful summary can be found in ‘Robert Craig: Miller Supreme Court Case Summary’ U.K. Const. L. Blog (26 January 2017)

[35] This includes legislation enacted by Parliament and the common law.

[36] [78].

[37] [40] – [57].

[38] [126] – [135].

[39] [194].

[40] See in particular [177].

[41] See R Greenslade, ‘How the press reacted to the article 50 verdict’ The Guardian 25 January 2017


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