The debate about the UK’s membership of the European Union has turned in large part upon the notion of control, “vote leave, take control” being the pro-Brexit campaign’s mantra. The idea that there has been a loss of control, and that the UK is increasingly governed from Brussels by an unelected, unaccountable “elite”, has fired the public imagination, giving the Leave campaign real traction. So too has the argument that control should be wrested from the EU by leaving it and re-asserting “sovereignty”. Leading Brexit campaigner Boris Johnson has thus argued that “you cannot express the sovereignty of Parliament and accept the 1972 European Communities Act” (which, among other things, gives priority to EU law over domestic law in the UK). Meanwhile, Nigel Farage, leader of the pro-Brexit UK Independence Party, wishes to see Britain re-establish itself as “a proud, patriotic country that has control of its borders, represents itself on the world stage and makes its own laws in our own sovereign Parliament”.
As these comments indicate, when the language of “sovereignty” is used in the UK, it implicates not only the sovereignty of the UK as a State, but also the sovereignty of the UK Parliament as an institution. The principle of parliamentary sovereignty, along with the (not unrelated) absence of a codified constitution, sets the British constitution apart from most others. And while parliamentary sovereignty and State sovereignty are distinct, the absolutist terms in which the former is sometimes understood colours — and skews — the way in which the latter is conceived of in the UK.
The principle of parliamentary sovereignty holds that the UK Parliament can make whatever laws it wishes; that no “higher” constitutional laws or principles constrain Parliament’s legislative authority; and that other institutions, including the courts, must accept as valid laws duly enacted by Parliament. This sort of untrammelled legislative power does not sound like a recipe for liberal democracy — and the fact that fundamental rights are generally respected in the UK, including by Parliament when it enacts legislation, is thanks not to legal control of, but political restraint by, law-makers. It is in this sense that the UK has a “political constitution”, meaning that it consists not only of legal but also of non-legal norms. This, in turn, means that — perhaps counterintuitively — something can be both “unconstitutional” (in the sense of conflicting with non-legal constitutional norms) and legal (because it does not conflict with legal norms).
The legal and constitutional implications of EU membership sit uncomfortably with this tradition of political constitutionalism, not least because the doctrine of the supremacy of EU law connotes its priority over even Acts of the UK Parliament. The implication that British law-makers are subject to legal constraint is one that is alien to the traditional British constitutional mindset, immediately suggesting that EU membership threatens — or even extinguishes — parliamentary sovereignty. But the sovereignty-based objection to EU membership goes further, for it is amplified by the idea that membership causes British legislators’ hands to be tied not simply by law, but by European Union law. In this way, considerations of parliamentary and State sovereignty fuse, forming the basis for rhetorically powerful objections to EU membership.
Of course, the UK does not find itself in a unique position: all Member States are subject to the principle that EU law is supreme. But the sovereignty argument has particular purchase in the UK — not only because legal constraints upon law-makers’ powers are anathema to the tradition of parliamentary sovereignty, but also because, according to some, the UK is peculiarly disadvantaged by the absence of a written constitution. For instance, the President of the UK Supreme Court, Lord Neuberger, has argued that while “Germany has a Constitution [that] enables a German court to say that German law sometimes trumps EU law”, such an option would be open “much more rarely, if at all, … to a UK court as we have no constitution to invoke”. On this analysis, the UK finds itself uniquely defenceless against what the celebrated English judge Lord Denning once referred to as an “incoming tide” of EU law that “cannot be held back”.
The legal reality, however, is more complex. The extent of the priority that EU law enjoys in the UK is (as a matter of domestic law) within the control of Parliament — a position affirmed by legislation enacted as recently as 2011. Section 18 of the European Union Act 2011 stipulates that EU law has effect in the UK only because UK law so provides. It follows that the priority enjoyed by EU law in the UK is the product of an exercise of parliamentary sovereignty, not a threat to it.
Recently, however, in the HS2 case, the Supreme Court went further. The issue was whether a parliamentary process that was to be used to consider proposals for the UK’s new high-speed rail network would provide the level of scrutiny required by the EU Environmental Impact Directive. This raised the question whether the courts could be required by EU law to examine the adequacy of parliamentary processes, bearing in mind the fundamental principle — reflected in Article 9 of the Bill of Rights 1689 — that parliamentary proceedings “ought not to be impeached or questioned in any court”. Although, in the end, the Court held that the Directive did not require it to do anything that would breach that principle, it nevertheless considered the general question whether EU law could require it to set aside fundamental constitutional principles. It concluded that in the event of conflict between such principles and EU law, UK courts should give priority to the former, the EU doctrine of the supremacy of Union law notwithstanding.
This was so, said the Supreme Court, because the terms on which EU law enters the UK legal system are controlled by Parliament — and when Parliament passed the European Communities Act in 1972, giving priority to EU law, Parliament was to be taken to have assigned such law only a qualified form of priority. In particular, it was not to be taken to have given it precedence over the UK constitution’s foundational principles. In the absence of a codified constitutional text, there is inevitably a degree of uncertainty about what those principles are. Nevertheless, this judgment demonstrates that the absence of a written constitution in the UK does not place it in a uniquely vulnerable position when it comes to the interaction of EU law and domestic constitutional values. To anticipate a point that is developed below, the HS2 case thus demonstrates the Supreme Court’s willingness — by privileging certain local fundamental values — to enforce what might be considered a form of constitutional subsidiarity.
The argument that the UK should leave the EU in order to restore sovereignty implies that EU membership presents a unique challenge to sovereignty — and that by leaving, that challenge would be definitively quashed. The truth, however, is that whether or not the UK remains a member of the EU, the notion of parliamentary sovereignty inadequately describes the reality of modern Britain’s constitutional architecture. Thanks to devolution, legislative authority in the UK is now dispersed in ways and to extents that have transformed the territorial constitution. And although devolution is technically understood to be a rescindable gifting of power by Westminster to other institutions, that analysis is increasingly difficult to sustain. For instance, section 63A of the Scotland Act 1998 — a provision inserted by the Westminster Parliament into the Act following the Scottish independence referendum — provides that “the Scottish Parliament and the Scottish Government are a permanent part of the United Kingdom’s constitutional arrangements” (emphasis added). This provision acknowledges that the in-effect irrevocable and substantial transfers of power that the UK Parliament has made to the devolved legislatures have instituted a new, quasi-federal chapter in British constitutional history — one that presents at least as great a challenge to the notion of parliamentary sovereignty as does EU membership. Yet in spite — or perhaps because — of this, devolution has proven to be very popular with citizens in relevant parts of the UK.
The fact that devolution amounts to a strong political — and now arguably quasi-legal — constraint upon the principle of parliamentary sovereignty demonstrates that that principle is not sacrosanct. Indeed, the concern of the average citizen has nothing to do with abstract legal questions about whether this or that constitutional arrangement impinges upon the sovereignty of the UK Parliament. But the average citizen certainly is concerned about whether power is exercised responsibly, whether those who wield it can adequately be held to account, and whether those who exercise power do so over, and form part of, a cohesive political community.
This suggests that the underlying concern in the UK is not so much about the sovereignty either of the UK Parliament as an institution of or the UK state as a monolithic entity, but about subsidiarity — albeit that the term “subsidiarity” has not much featured in the Brexit debate, not least because of its undertones of European technocracy. Devolution has been considered a success because, consistently with subsidiarity, it has re-sited power in ways that allow it to be exercised closer to those who are liable to be affected. This has not (quite) fatally weakened the UK as a political unit — although the closeness of the result in the 2014 Scottish independence referendum certainly evidences considerable erosion of the ties that bind Scotland to the rest of the UK. But it does demonstrate that far from wishing to see power vested in a single, central institution, there is a great appetite in the UK for the dispersal of power — something that is now being extended to England, albeit modestly and unevenly, under the Cities and Local Government Devolution Act 2016.
The question then arises whether that appetite extends to the distribution of power not only ‘down’ to local — such as devolved — institutions, but also ‘up’ to transnational institutions such as the EU. Subsidiarity, after all, does not imply devolution ad infinitum; it is equally capable of accommodating governance at national — and supra-national — levels, given that some issues can most effectively be dealt with in such ways. And the transmission of authority to supra-national institutions is not inherently any more of a challenge to sovereignty — in either its parliamentary or State forms — than is devolution. Indeed, the very fact that the EU referendum is being held is evidence of the reversibility of the arrangements into which the UK and EU have entered under the the EU treaties, and hence of the fact that EU membership is not an existential threat to British sovereignty, such as it is. More than that, however, the foregoing analysis reveals the argument that the UK should leave the EU so that sovereignty can be restored to be the gross oversimplification that it always was. The notion of sovereignty increasingly fails to capture both the reality of the UK’s place in what is (EU or no EU) an increasingly interconnected legal world, and the way in which power is diffused across the UK rather than being jealously concentrated in a single sovereign legislature in London.
It follows that attempting to frame the question of Britain’s EU membership in terms of whether sovereignty should be restored lends the debate a binary character that is ultimately specious. The real issue, then, is not whether membership of the EU is or is not compatible with some absolutist notion of sovereignty, but whether the UK’s relationship with the EU reflects an acceptable balance of power between national and supra-national tiers of government. And that, inevitably, is a matter upon which voters will, and do, differ sharply — not least because of their radically contrasting views about the extent to which the European Union is a political community of which they are, feel, and want to be a part. “Vote leave, take control” is an undeniably catchy slogan. But its very simplicity — and the implication that EU membership is all that stands opposed to a pristine British notion of sovereignty — does a disservice to the complexity, not to mention the momentousness, of the decision that the British electorate must take today.