The phrase ‘Brexit means Brexit’ dominated British politics in the early years following the referendum. The tautological structure of this statement reflected a deeper problem: the meaning of the referendum was unclear from the beginning. Arguably, this was because the legal meaning of Brexit was contested on (at least) two different axes: first, ‘what is the legal significance of the referendum?’, and second, ‘what legal relationship with the European Union was agreed by the referendum?’

Unlike the alternative vote referendum of 2011, or the devolution referendums of 1998, the Brexit referendum was not ‘self-executing.’ In the legislation that triggered those earlier referendums, law was already drafted that would take effect if voters supported the ballot propositions. No such process was clarified by the European Union Referendum Act 2015. Courts have repeatedly acknowledged this ambiguity. In Cherry/Miller, the Supreme Court said that the referendum was not legally binding, but that it had been treated as both ‘politically and democratically binding.’ [7] What that phrase means was and remains uncertain, however. Cases such as Miller I and the Lord Advocate’s Reference may demonstrate that the Brexit referendum had legal consequences – but those consequences were not automatic.

The second ambiguity concerned the destination implied by ‘leave’ – and would be bitterly fought over, domestically just as much as in negotiations with the EU. Unsurprisingly, the resulting relationship with the EU reflects a spectrum of different models. Northern Ireland remains partially governed by EU law in relation to goods, while Great Britain participates in a zero-tariff, zero-quota trading framework which is somewhere between EEA membership and a comprehensive free trade agreement. Goods is the high-water mark of cooperation, though. Free movement of people has largely ceased, and services are governed through a limited and bespoke set of arrangements; including the possibility of special equivalence decisions in financial services.

These disagreements about Brexit remain relevant to the status of Northern Ireland, the role of referendums, and the extent of executive power. The many meanings of Brexit are not all established yet.

Leah Trueblood is Senior Lecturer in Law at the University of Surrey.

Note: The views expressed in this post are those of the authors, and not of the UCL European Institute, nor of UCL.