20-21 February 2016David Cameron, having promised in 2013 that a future Conservative government would offer a referendum on Britain’s membership of the EU, announces the date of the vote: 23 June 2016. The next day, Boris Johnson, then the mayor of London, says he will campaign for leave.Bernard Jenkin, a senior Conservative backbencher, campaigned for leave: The starting gun was really fired in the [2013] speech. I went to see David Cameron after that and begged him not to hold an in/out referendum, simply because it would smash the Conservative party. He said to me: “I know 50 Conservative MPs...