On May 22, one Boris Johnson gave his forecast for the UK’s post-referendum future: “Given the choice between taking back control or being sucked ever deeper into the federal superstate, the British voted for independence on June 23. To no one’s very great surprise, Project Fear turned out to be a gigantic hoax. The markets were calm. The pound did not collapse.” Alas, untrue. After the biggest ever proportional two-day decline, the pound touched a 30-year low against the dollar. Standard & Poor’s and Fitch have downgraded UK public debt. Investors have savaged bank shares. So far, the experts, dismissed by Michael Gove, justice secretary, have been proved right.

Mr Johnson is to economic forecasting what England is to football. Any well-informed person knew that a vote for Brexit would inflict medium-term pain on the economy. The Treasury might even have been underestimating the shock. It would be astonishing if there were to be no recession. This self-inflicted folly will hurt millions of innocent people. It is likely that buyers’ remorse will soon set in. Voters might conclude that the leaders of the Leave campaign were fools or liars.

It is easy to sympathise with the view of Harvard’s Kenneth Rogoff that the hurdle for a change to the status quo had to be far higher than 50 per cent of votes in a referendum on an issue as profound as this one. As it is, 36 per cent of eligible voters have been allowed to decide “without any appropriate checks and balances”. This is just one aspect of the irresponsibility shown by David Cameron, Britain’s prime minister, throughout this immensely important process. It is not surprising, for example, that he found it hard to argue credibly for Remain after spending more than five years denigrating almost everything about the EU. He has proved calamitously short-sighted.