Boris Johnson criticises Barack Obama for urging Britain to stay in EU

United States president Barack Obama urged British prime minister David Cameron not to hold a referendum on European Union membership, a leading former coalition partner of David Cameron has claimed.

Former Liberal Democrat cabinet minister David Laws claimed that Mr Obama warned Mr Cameron against the plan during a meeting in London, but the latter insisted he had to do so to keep the Conservative Party united.

Mr Obama returns to London later this month, where he is determined to give a public warning to voters that they should not vote to quit the EU in the June 23rd referendum.

"The approach he will take is that we have no closer friend in the world, and if he is asked his view he will offer it. He will be very straightforward and candid as a friend on why it's good for the UK to remain in the EU," said Ben Rhodes, the president's deputy national security adviser.

The Brexit referendum officially kicked off on Friday with a series of speeches by leading pro-exit campaigners, such as Boris Johnson, Michael Gove, Chris Grayling, Iain Duncan Smith and the United Kingdom Independence Party leader, Nigel Farage.

Mr Johnson criticised Mr Obama, saying: "I honestly don't mind the idea of him joining the debate. Where we do part company, and where I do mind is that it is plainly hypocritical for America to urge us to sacrifice control – of our laws, our sovereignty, our money and our democracy – when they would not dream of ever doing the same."

Mr Farage was even more critical. “President Obama should butt out,” he said. “This is an unwelcome intervention from the most anti-British American president there has ever been. Mercifully, he won’t be in office for much longer.”

Meanwhile, the leader of the Roman Catholic Church in England and Wales, Cardinal Vincent Nichols, warned that starting "down the path of division" would "almost inevitably" lead to "further division". "There is a long tradition in Christianity, and Catholicism in particular, of believing in holding things together. There is a strong tradition in the Catholic vision of life that to start down the path of division almost inevitably leads to further division," he said.

Speaking in Washington DC, British chancellor of the exchequer George Osborne warned that mortgage rates would rise if the UK quits, as families paid the price of market instability.

“If you look at the view of the experts here at the IMF in Washington, it’s pretty clear that if Britain votes to leave the EU then prices will go up and there will be instability in financial markets,” he told Sky News.

Meanwhile, the London School of Economics’ Centre for Economic Performance claimed that an EU departure would cut £2,200 off household incomes and reduce overseas investment by a quarter over the next decade.