The United Kingdom is to leave the European Union, partly in order to protect the right to self-government of the UK as a nation state as expressed through the sovereignty of the Westminster Parliament. Interestingly, the reaction to the decision to leave the EU reveals the degree to which through a combination of devolution with increased recourse to referendums, the United Kingdom has drifted into being a kind of voluntary grouping of sovereign nations that bears significant similarities to the European Union.

The orthodox view that the Queen in Parliament is the ultimate source of political and legal authority in the United Kingdom has been under some pressure in recent times. For example, some judges have speculated obiter that extreme measures curtailing judicial review may not be recognised as law. However, such a proposition is highly controversial and has never been fully tested. By and large, the legal status of the Westminster Parliament as the supreme law maker remains largely intact. Nevertheless, political practice in recent decades raises significant doubt as to whether, as a matter of day to day political reality, the supremacy of the UK Parliament continues to apply.

Referendum as Highest form of Constitutional Authority

The major change in this regard has come through the increased use of referendums. Beginning with the EEC referendum in 1975, the idea that some matters of fundamental importance to the constitutional structure of the state ought not to be decided by Parliament alone but ought also to be subject to referendum has gained significant traction. This view was explicitly endorsed by Prime Minister Cameron in the House of Commons in the aftermath of the Brexit vote.

The use of referendums has increased markedly in the last 20 years. Scotland and Wales held referendums on devolution in in 1979 and 1997. Northern Ireland held a referendum on the Good Friday Agreement in 1998. Various English regions and cities have held referendums on establishing directly elected mayors or assemblies and in 2011 a referendum on the electoral system for Westminster elections was held. In addition, the European Union Act 2011 provided that a referendum would have to be held in the event that any further powers were transferred from the UK to the European Union.

The practice of using referendums to decide matters deemed to be of the utmost constitutional significance established a source of authority, the electorate voting in a referendum (either of the UK or of a constituent part thereof), as a source of political legitimacy that outranked that of the Westminster Parliament. This was particularly notable in respect of the European Union Act 2011 which was based on the premis that it would be illegitimate for Parliament to agree to transfer further powers to the EU without the consent of the people of the UK via referendum. Implicit in this is the idea that only the people acting by referendum had the authority to transfer powers to the EU and that there is therefore a category of decision that the Westminster Parliament lacks political authority to make.

Recognition of Local Sovereigns Acting by Referendum

The sanctification of the referendum as the ultimate source of political authority in the UK constitutional system has combined with the process of devolution to significantly restrict the authority of the Westminster Parliament and the status of the United Kingdom as a nation-state (even a plurinational one). In theory, the devolved institutions are creations of legislation of the Westminster Parliament and could be abolished by the Westminster Parliament if it so chose. Politically, this is not the case. The Northern Irish institutions form part of an international agreement with the Republic of Ireland in respect of the peace process in Northern Ireland so as a matter of public international law, the UK ought not to unilaterally abolish them.

More significantly for my purposes, the creation of the Scottish and Welsh institutions came into being following referendums, a form of legitimation increasingly recognised as superior to Westminster legislation. In each case the referendum was not UK-wide but was confined to the devolved nation in question thus constituting a local sovereign in each devolved nation that outranked Westminster as a source of political authority. In these circumstances, it is hard to see how the Westminster Parliament could actually exercise its right to abolish either devolved legislature without putting such a decision to a local referendum.

The decision to expand the powers of the Welsh Assembly in 2011 was the subject of a Wales only referendum and, most importantly, the issue of Scottish independence was subject to a Scotland-only referendum in 2014. The UK Government was clear that the issue of Scottish independence was for Scotland alone to decide by means of referendum. Although the UK authorities had to draft an Order in Council in order to permit the Scottish Parliament to pass legislation to hold the referendum and although the UK government negotiated matters such as the nature of the question and the electorate with the Scottish government, it was clear that all parties regarded the Westminster Parliament as being obliged to give effect to the outcome of the vote.

No Substantive Restrictions on Local Sovereignty

In short, the Scottish electorate acting by referendum, not the Westminster Parliament, has effectively been recognised as the supreme authority for matters relating to Scotland’s status as part of the UK (a situation that presumably applies by analogy to the Welsh electorate). Indeed, the Westminster Parliament did not even feel entitled to impose any substantive limitations on the exercise of Scottish electoral sovereignty. While in Canada the federal government has, through the Clarity Act 1999, imposed a supermajority and other requirements on any future referendum decision in favour of Quebec leaving Canada, in 2014, the UK authorities were will to accept a one vote majority as sufficient.

The notable deference of the UK authorities to the supreme decision-making power of the Scottish electorate makes the UK resemble more of a mini-EU; a voluntary federation combining nations which retain ultimate sovereignty including an almost unfettered right to leave the Union. The failure of the UK authorities to impose supermajority or other conditions (beyond the clarity of the question put) in the Scottish referendum means that, just as EU member states may according to Article 50 of the Treaty on European Union, leave the Union “in accordance with their own constitutional requirements” the Scottish electorate is free to leave the UK through a process largely free of constraints imposed by the UK authorities.

Brexit, “Material Change” and a the Right to Hold Second Referendum

Furthermore, following the 2014 referendum, the Scottish National Party leadership suggested that a “material change” in the relationship between Scotland and the rest of the UK could trigger a further independence referendum. The outcome of the UK’s 2016 EU membership referendum in which a majority of Scottish voters voted to remain in the EU has been characterised as such a change by the Scottish Government which is now actively considering a second referendum.

It has to be conceded that holding a second referendum would be legally complicated. In 2012 the Advocate General for Scotland disputed assertions on behalf of the SNP that a referendum could lawfully be organised by the Scottish Parliament. SNP leaders had argued that although the question of the status of the Union was reserved to Westminster, as a referendum would only be advisory, there was no legal impediment to it being organised by the Scottish Parliament. The Advocate General forcefully argued that such a move would nonetheless involve a clear attempt to stray into areas that had been allocated by law to Westminster and would therefore be contrary to the rule of law. In the end, this issue did not need to be resolved as an agreement was reached under which, as noted above, the 2014 referendum was organised by the Scottish Parliament on the basis of legal authority temporarily transferred by the Westminster Parliament by means of an order in council.

This authority, was however, a once off authorisation to hold one referendum and it lapsed on 31 December 2014. Legally, therefore, the Scottish Parliament would have significant obstacles in unilaterally organising a second referendum. However, politically, it may be impossible to resist a demand for such a vote if it were backed by a political majority in Scotland. Indeed, even those such as Scottish Conservative leader Ruth Davidson who oppose to Scottish independence have not suggested that the Scottish electorate lacks the authority to secede from the UK on this basis. Although in theory, Westminster could refuse permission for a further refrendendum, having accepted that referendums are provide a greater degree of legitimacy that votes of the Westminster Parliament and that Scotland’s status as part of the UK is for Scots alone to determine, it is difficult to see how Westminster could then refuse to allow a referendum to take place or to refuse to recognise the result of a referendum organised by the Scottish Government without the consent of Westminster.

If that is the case, this leaves Scotland’s relationship to the UK very much like the UK’s relationship to the EU prior to the referendum. Indeed, the analogy goes further, the SNP’s identification of a “material change” in the relationship between Scotland and the UK as grounds for triggering an independence referendum bears a remarkable resemblance to the provisions of the European Union Act 2011 under which the Westminster Parliament set down that any further transfer of powers to the EU by the UK would require approval in a referendum.

Of course, there has always been a degree of ambiguity about the relationship between nation and state in the UK. Northern Ireland’s status within the UK has been contingent on the wishes of a local majority since its inception. Indeed, between 6 and 7 December 1922, Northern Ireland was actually part of the Irish Free State for 24 hours, following the entry into force of the 1921 Anglo-Irish Treaty until the Parliament of Northern Ireland passed a resolution activating the right given to it by the Treaty to leave the Irish Free State and remain part of the UK. This deference to a local majority was repeated in the Ireland Act 1949 which declared that Northern Ireland would remain part of the United Kingdom unless the Parliament of Northern Ireland decided otherwise. The 1998 Good Friday Agreement also included a binding obligation to give effect to the choice of a majority in Northern Ireland to leave the UK. Given that Northern Ireland had been created in order to accommodate the will of a majority in a particular region of Ireland to remain in the UK, it is not surprising that that the continuance of such a majority was seen as necessary for the status of the Northern Ireland within the Union to be maintained. Interestingly, however, the duty now recognised in UK law is to abide be a decision to transfer Northern Ireland to another state (the Republic of Ireland) and does not explicitly grant a right to Northern Ireland to become an independent state.

Given the violence caused by disputes around Irish independence and the reunification of Ireland, Northern Ireland has always been someting of a special case. Independence movements in Scotland and Wales have been notably different. In both cases the growth of pro-independence movements came after very significant periods of time where the status of each nation as part of the UK had been the subject of near unanimous agreement. The fact that there was so little support for Welsh or Scottish independence until relatively recently meant that the UK did not have to consider the conditions under which the Union of England, Scotland and Wales could be undone.

In the case of Scotland it is true that elements of the Union and the authority of the Westminster Parliament have been the subject of dispute over the years. For example claims had been made that the conditions contained in the Act of Union of 1707 constituted substantive limits on Westminster’s legislative power and Scottish judges have on occasion, reserved their position on this matter. Most famously, in McCormick v Lord Advocate in 1953 the Lord President of the Court of Session, Lord Cooper stated that absolute parliamentary sovereignty was an English principle that had no counterpart in Scots law. Noting that:

“…the Treaty [of Union] and associated legislation … contain some clauses which expressly reserve powers of subsequent modification; and other clauses which either contain no such power, or emphatically exclude subsequent alteration by declaration that the provision shall be fundamental and unalterable in all times coming …”

he concluded that he could not understand how the orthodox English view of parliamentary sovereignty could be reconciled with such provisions. However, this assertion of limits on Parliamentary authority to change the terms of the Union lost much of its impact in the light of Lord Cooper’s ultimate conclusion that challenging alleged breaches of the Act of Union in court was not possible as it was

“clear that there is neither precedent nor authority of any kind for the view that the domestic courts of either Scotland or England have jurisdiction to determine whether a government act of the type here in controversy is or is not conform to the provisions of the Treaty …”

Limits on Westminster’s ability to legislate in relation to the Union foundered therefore, on the basis that there was an absence of institutions empowered to pronounce definitively on these matters.

Devolution and the use of simple majority local referendums to definitively decide questions of independence have changed that element of the equation. The creation of a Scottish Parliament gives institutional voice to a Scottish demos. Perhaps even more significantly, the recognition of the supreme authority of the Scottish electorate in matters of independence provides a means through which unilateral changes to the terms of the Union can be met by a claim to secession on the part of Scotland.

The UK as a Mini-EU

Though the UK has had a very defensive attitude to its role as a self-governing nation-state in its relationship with the EU it has, in recent decades, had a curiously relaxed attitude to the same issue in relation to the status of its constituent parts. The ad-hoc responses that emerged when the Scottish referendum became likely appeared to pay remarkably little attention to the a the idea that a national community must involve some degree of a “for better or for worse” commitment. As things stand, Scotland’s status in the United Kingdom appears to be strikingly easily breakable, being dependent solely on the desires of the Scottish electorate and on the basis that the terms membership of the UK do not change and continue to be provide net benefit to Scotland.

This places the UK at some distance from predominant ideas of what it is to be a nation-state and is unlikely to be sustainable. Change is inevitable in the world so the terms of Scotland’s relationship with the UK will inevitably change over time. In addition, at some stage the economic planets may well align so that it is, for a period of time, economically advantageous for Scotland to leave.

Of course the UK has always been a “union state” where the institutional existence of the constituent parts was never extinguished but lived on in the form of distinct linguistic and cultural traditions, separate legal systems and national claims of the different parts of the Union. Yet such diversity is not unique. Some German länder were independent states until much more recently than Scotland. Spain has even greater linguistic diversity than the UK as well as distinct institutions that embody the national claims and on the part of Basques and Catalans. The Spanish government’s approach to Catalan independence claims has been to assert that Spain is a nation and the claims to separation cannot be entertained. The contrast to the UK, where Westminster will defer to a once off majority in favour of independence even in circumstances where polls show that support for independence collapses if voters think it would cost them £500 per annum, could hardly be starker

The violence that had ensued when the United Kingdom forcibly tried to resist the move for Irish independence a hundred years ago made a Spanish-style response to the issue of Scottish independence unthinkable for the UK but little thought has apparently been given to intermediate, Canadian-style options or to the probably unsustainably feeble nature of the bond between the constitutent parts of the UK that results from an entirely deferential approach to the local electorates of each part of the Union.

Constitutional practice over the last twenty years in the UK appears to show that constituent parts of the United Kingdom may claim independence after many decades, if not centuries, of voluntary union without surmounting any greater obstacle than a one vote majority in a once-off referendum. Therefore, while the vote in favour of Brexit may show the weakness of confederal bodies of nation-states such as the EU, by raising the prospect of Scottish departure once more, it also highlights how the UK has drifted into becoming something like such a loose association of sovereign nations itself.

Ronan McCrea is a Senior Lecturer in Law at University College London.

(Suggested citation: R. McCrea, ‘Is the United Kingdom a Mini-EU?’, U.K. Const. L. Blog (18th July 2016) (available at https://ukconstitutionallaw.org/))