political agenda increasingly being set by the UK Independence Party (UKIP), led by the MEP Nigel Farage. Ultimately, David Cameron chose to escalate his response, and in his Bloomberg speech in 2013, committed to include a promise to hold an ‘in / out’ referendum on EU membership in the Conservative manifesto for the 2015 general election. A diluted version of this position was set out by the Labour Party in response – an ‘in / out’ referendum would be held in the event of major change to the EU treaties. Yet while the idea of a national referendum on EU membership – in one sense or another – seemed therefore to be attracting support from both major political parties, many regarded the prospect of it actually coming to fruition as unlikely. Key indicators, such as opinion polls and historical precedent, meant that another hung Parliament was widely expected to be the outcome of the 2015 election, and there was consequent suspicion that, if Cameron was returned to office at all, the EU referendum manifesto pledge would be something he would gladly bargain away with prospective coalition partners, despite advance protestations to the contrary. The surprise result of a Conservative majority government in 2015 meant that the returning Prime Minister could not rely on coalition with the Liberal Democrats to dilute his manifesto commitment. With the referendum to be held at some point before the end of 2017, David Cameron launched an attempt to renegotiate the UK’s membership of the EU. Proposals for change were agreed across four ‘baskets’ representing key concerns on immigration, sovereignty, euro governance, and competitiveness. Many were surprised at the level of concessions ultimately made by the EU, but even this package was never likely to satisfy the most ardent eurosceptics. While it was sufficient – finally – to convince the Prime Minister that he could recommend a vote to remain to the electorate, the Cabinet was split, and the ensuing campaigns left much to be desired. Little attention was ultimately given to the terms of the deal agreed through the renegotiation, and still less to the major ‘balance of competences’ review conducted between 2012 and 2014 under the coalition government, which explored in some detail the suitability of the existing division of power between the EU and the UK. Instead, the ‘leave’ campaign prioritised concerns associated with immigration and sovereignty, and made deceptive claims about the extent of the UK’s financial contribution to the EU, and about
UK constitutionalism as a contributory factor in generating Brexit? To explain in detail the causes of the UK’s decision to exit the EU is clearly a task which extends well beyond constitutional analysis. It is also a task which will take time, although there has already been much debate as to the initial indications. Clearly significant was the fact that the commitment to freedom of movement required by EU membership clashed with concern about immigration levels which were cynically, even viciously, exploited by some prominent leave campaigners. Electoral demographics obviously had an important impact, particularly the enhanced engagement of older votes, as did the failure of the then Prime Minister David Cameron to bring his party with him on a remain vote. Yet in addition to these diverse contributing factors we have reason to question whether there was a constitutional element to the result of the Brexit referendum. Was the nature of UK constitutionalism itself a factor? As the campaign developed, it was notable that constitutional themes and ideas seemed to resonate in the political and public discourse to a greater extent than might have been expected, notwithstanding the fact that whether the UK should have retained its membership of the EU is obviously a ‘constitutional’ question with ‘constitutional’ implications. This does not, of course, mean that constitutional considerations dominated the debate. Yet as seemingly well-established strategies for electoral success – most notably the ‘it’s the economy, stupid’ approach – failed ultimately to persuade a majority of the electorate to maintain the status quo, the leave campaign’s pseudo-constitutionalist call to ‘take back control’ was effective in capturing and combining a range of issues. If we look beyond the superficiality of this message, we may discern a number of constitutional dynamics potentially at work in the Brexit vote. The constitutional underpinnings of the referendum result – or of the long-cultivated eurosceptic environment in which the decision to exit the EU was reached – may include, among others, a discomfort with the ‘eurolegalism’ which has arguably come to define the European project, and the resulting changes in domestic law and practice which such a supranational philosophy prompts.
It is not my purpose to endorse these claims as to the (potential) constitutional underpinnings of Brexit, nor to condemn the domestic reliance on the idea of parliamentary sovereignty as a central organising conception of the UK constitution. Instead, I simply want to consider: if there were constitutional factors which contributed to the referendum decision to leave the EU, such as those sketched above, can they be responded to? Or are these really constitutional concerns which extend beyond the UK’s relationship with the EU? This will be important in two ways: first, regarding the future development of the UK constitution, and secondly, regarding the future of the post-Brexit EU. First, the uncertainty about any underlying constitutional causes – as about much else concerning Brexit – makes it far from straightforward to anticipate how the future development of the UK constitution could respond to this agenda. Again, much would depend on the future substantive relationship agreed with EU – if the UK were to end up formally outside of the Union, but within related structures such as the single market, and consequently subject to fields of EU law, it would be open to question whether this could amount to a restoration of sovereignty in any sense. Indeed, many might suggest that in such circumstances the UK’s power to control its own affairs would be diminished, given the loss of influence over EU law-making this would necessarily entail. Even if the UK were to negotiate a position entirely apart from the EU and its legal norms, there are other international institutions and power structures with which we would be required to engage – will the accountability gap be any less apparent, for example, with respect to the WTO, or the institutions which could be empowered under international trade agreements? It is difficult to avoid the conclusion that if Brexit is intended to herald a return to a romanticised constitutional past it will be a significant disappointment. A UK constitution founded on the principle of untrammelled national sovereignty is not just impossible under modern conditions, but the very notion is a myth – this much should be readily apparent in a tradition which is sceptical of the utility of formal limitations, while recognising that political constraint can provide the core of a constitutional framework. The unavailability of a constitution that is invulnerable to European influence does not mean abandoning all ideas of (parliamentary) sovereignty, appropriately understood, operating in a domestic context. It also does not mean that the broad constitutional concerns