The “second referendum” or, as some prefer, a first referendum on the deal, has become one of the key arguments of the Brexit debate. The political argument is fairly simple: the British people voted on whether or not to be members of the European Union, which gave a mandate to the government to negotiate the terms of exit. Given that those terms are unknowable at the outset of the negotiations, it is reasonable to check with the British people whether or not they are content with the deal on offer with a referendum at the end of the process. The counter-argument is also fairly simple: the people have spoken and decided they want to leave the EU. That is the end of the matter. The debate rages.
But outside the political arguments, there is a little-known legal requirement for the government to hold a second referendum. The reasons for this are buried in the time of the coalition government, which in this febrile political age feels like ancient history. In 2011, long before any talk of an in/out referendum, the European Union Act was passed. This was one of David Cameron’s many attempts to manage the increasing Euroscepticism of his Conservative Party which reached its zenith in the 2016 referendum. The 2011 Act promised that no government would be able to amend or replace EU treaties without an Act of Parliament, and no law which would increase Brussels’ power over the UK could be passed without a referendum.