On Friday, British Prime Minister David Cameron negotiated some concessions for Britain if it remains in the European Union, and on Saturday he announced that Britons will vote on whether to stay in the EU or exit on June 23. On Sunday, London's popular mayor, Boris Johnson, dealt an early blow to Cameron's bid to keep the UK in the EU, arguing in favor of a "Brexit" in his weekly column in The Daily Telegraph. "We are seeing a slow and invisible process of legal colonization, as the EU infiltrates just about every area of public policy," he wrote. "A vote to Remain will be taken in Brussels as a green light for more federalism, and for the erosion of democracy."
Johnson, a Conservative like Cameron, is now considered the de facto leader of the pro-exit camp, though he downplayed such a role on Monday. "There will be plenty of time to talk about Europe and the great future that Britain can have outside the European Union in the next few weeks," he said. Early Monday, the British pound had its sharpest drop against the dollar in 11 months, and also dropped against the euro, plus the betting odds of a Brexit rose 4 percentage points to 33 percent, based solely on Johnson's endorsement.
The Labour Party and Scottish Nationalist Party both back remaining in the EU, but the Conservatives are deeply split. Johnson's endorsement of the exit camp is seen by many as a way to position himself to take over party leadership after Cameron steps down, though one person who doesn't share that view is Johnson's father, Stanley Johnson, a Tory former member of the European Parliament. "To say that this is a careerist sort of move would be a total travesty," he told BBC radio on Monday. "I can't think of any more career ending move than to do what he did yesterday."