EU referendum: George Osborne hits out at Boris Johnson for backing Brexit as Tory tensions over Europe grow

Mr Johnson’s decision to play a leading role in the Leave team has infuriated David Cameron and Mr Osborne

Chancellor of the Exchequer George Osborne appears on The Andrew Marr Show (Getty)

Tory tensions over the European Union referendum have been laid bare again after George Osborne took a series of swipes at Boris Johnson over his backing for Brexit. The Chancellor accused the Mayor of London of campaigning for Brexit out of political ambition, and mocked his support for a Canadian-style free trade deal with the bloc.

Mr Johnson’s decision to play a leading role in the Leave team has infuriated David Cameron and Mr Osborne who believe he has acted opportunistically to court favour among Tory activists for a leadership bid.

The Mayor has retorted that he has a long history of criticising Brussels dating back more than 20 years when he was a reporter covering the EU.

Mr Osborne told BBC1’s Andrew Marr Show that Canada’s trade negotiations with the EU had so far lasted seven years and were still not complete.

He said: “I don’t want us to be Canada. I want us to be Great Britain. In the end this is not some political game. This is the biggest decision facing this country for 50 years.” In an apparent reference to his rival’s widely criticised appearance on the show last week, Mr Osborne said he would not “sit here and blather away and not actually do anything”.

A new book serialised in The Mail on Sunday claimed Mr Cameron was “petrified” of Mr Johnson challenging him for the leadership, telling the former Deputy Prime Minister Nick Clegg that the Mayor is “clearly after my job”.

Asked about the book by the former Lib Dem cabinet minister David Laws, Mr Osborne replied: “I don’t think it’s the greatest … revelation in human history to discover Boris Johnson is interested in a job in government.”

The Prime Minister is also said to have confided in Mr Clegg that Michael Gove, the Justice Secretary, had “gone a bit nuts recently” and was driving him “around the bend”.

Mr Gove, who is one of six cabinet ministers to support Brexit, told a private meeting of Tory and Lib Dem ministers that plans to hold the referendum were “completely barmy”, the book claims.

The book, which has been written with Mr Clegg’s co-operation, is likely to open the former Lib Dem leader up to criticism after he recounts a talk with the Queen in which he outlined changes to the rule of royal succession.

Mr Clegg was critical of attempts to “drag the Queen” into the referendum campaign after comments she was alleged to have made about the EU were leaked to a newspaper.