
In January 2013, David Cameron committed the Conservative Party to an “in-out” referendum on Europe, a promise that was duly incorporated in the party’s manifesto for the 2015 Election and delivered in the European Union Referendum Act 2015. The Act passed the Commons with 544 votes to 53 in favour (only the Scottish National Party opposed it). Parliament had thus determined that Britain’s constitutional settlement with Europe was a question on which it wished to be advised by the British public in a referendum (the outcome is advisory, not legally binding).
The advice the British public – at least the 37 per cent of eligible voters that opted to leave the European Union – gave Parliament on 23 June 2016 was clear. The political establishment has, for the most part, accepted that it ought to be acted upon. As Theresa May, the leading contender to replace Mr Cameron, put it when opening her leadership campaign: “Brexit means Brexit.” But, as more than a few Britons were furiously googling the day after the referendum, what exactly does “Brexit” mean?