What’s done is done, or so Richard Ekins has forcefully argued about the result of the referendum held on June 23^rd. Whilst, as he notes, there may be real questions about whether, for example, the issue of continued membership of the EU ought to have been put to the people rather than reserved for Parliament, or about the conditions under which a geographically fractured vote should bind all of the constituent parts of the UK, these should have been aired before and not after the vote. Why can such issues not be raised retrospectively? ‘The decision to proceed [by way of referendum],’ Ekins argues, ‘is itself an important public decision that fairly governs how we jointly are to decide.’ Having fixed on a particular decision making process, he suggests, our political representatives are now duty bound to abide by its result. The referendum, Ekins concludes, ‘should be respected and not undone.’

We can take these issues separately, starting with the notion that the result should not now be undone. It is true that, having decided to hand the question of EU membership to the electorate, it would be unprincipled for this Parliament to walk back on its own decision. So too our elected representatives should not, without more, push for a second referendum on the same issue. As Ekins suggests, ‘the dissatisfaction of some with the outcome is not a reason to repeat the exercise.’ A material change of circumstances external to the mere fact of voter discontent may justify revisiting the question in the future, but disappointment with the result is itself no reason to do so.

What, however, does the vote require such that it might be respected? Notoriously, there are many different ways in which the decision to leave the EU might be realised, from continued membership of the European Economic Area through to engagement with the EU on World Trade Organisation terms only. Given that the choice amongst such possibilities involves radically different versions of the UK’s long-term future it is right to ask whether the current government enjoys a mandate either (i) to decide for itself as between reasonable options, or (ii) to fulfil one such option because made salient by the vote to leave. I will argue that neither possibility is made out and that, as a result, the government must go back to the people in order to secure the legitimacy of its chosen terms of exit. I shall also say something about the bearing of the referendum result on possible electoral programmes.

First, then, does the current government enjoy a mandate to decide the terms of our political future outside of the EU? The promise to hold a referendum, the Conservatives’ manifesto pledge, cannot be understood to licence such a choice: manifesto promises secure the legitimacy of specific political outcomes, not the capacity to decide between many possible such outcomes. Nor can the result of the 2015 election be said to bestow such authority. Under a new leader, the government of late 2016 will be substantially changed from that which emerged victorious from the previous election. Whilst the ability to continue in government depends only upon the formal capacity to command the support of the House of Commons, the substantive legitimacy of later iterations of any particular government depends upon the continuity both in platform and personnel with the original vessel in the ship of Theseus sense. The problem here is that almost all the planks will have been replaced at once.

What, however, of the referendum result itself? Does this license a particular decision about the UK’s political future? Some have been quick to suggest that the result provides a mandate to close Britain’s borders and to prefer protectionist policies ahead of free movement, the leave campaign having fought hard on the issue of immigration. For reasons of political fairness, however, the referendum result cannot be understood to have settled anything other than that which it was intended to. Just as remain campaigners should not now argue that the referendum decided less than it did – that, for example, the choices of certain leave voters were invalid because cast in protest – so too it cannot now be argued that the referendum decided more than it did, by validating one vision of exit as opposed to any other.

Enjoying no mandate for its own choice of terms for departure and not being required by the referendum result to endorse any one such possibility, reasons of political legitimacy favour the government taking its plan for the future of the UK to the people, most obviously by way of general election. Doing so is now regulated by the Fixed-Term Parliament Act 2011. Section 2 (1) allows for an early election given the support of two thirds of MPs, and section 2 (3) for the same following a vote of no confidence, passed by simple majority and subject to a two-week period during which the house may reverse its decision. It is an important question whether the commons would be justified in passing such a motion if the government attempted to move decisively on a particular plan for exit without first seeking a fresh political mandate.

What bearing should the referendum result have on the electoral programmes of political parties going into a general election? Having campaigned for the referendum some might consider the Conservatives disingenuous if they were to abandon its outcome. Other parties would be right to conclude that they themselves owe no special duty of fidelity to the result. Just as UKIP would fairly have been able to continue with its central message on the assumption of a reverse decision on June 23^rd, so the decision should not now act as a political straitjacket for those who take a different view. Nor should the issue of fidelity be determined by the way a party’s supporters voted in the referendum, for the aim of party politics is not preference satisfaction given an assumed base. Ekins tells us that MPs should now see it as their duty to ‘loyally to implement’ the referendum decision ‘while continuing to argue about [the] detail’. It is there, of course, that the devil lies.

Thomas Adams is a Research Fellow in Law at Corpus Christi College, University of Cambridge.

(Suggested citaiton: T. Adams, ‘Is There a Mandate Here?’, U.K. Const. L. Blog (9th Jul 2016) (available at https://ukconstitutionallaw.org/))