Osborne must address the doubts the City has about his economic credentials.

During the bank holiday weekend, an email was circulating among high-ranking City financiers with the intriguing subject heading: ‘Message from George Osborne’. It was not a hoax. An executive from a fund management firm had written to the shadow chancellor’s office asking what plans the Conservatives had to reduce the deficit, as he had not read about such plans in the newspapers. He was sent a reply — which so shocked him that he sent it to every merchant bank from London to Hong Kong. ‘It looks light on content, to say the least,’ he wrote. ‘The currency markets smell blood in the water.’

It was a classic case of a political move looking mighty stupid in the real world. A junior aide in Mr Osborne’s office — until recently a secretary working for a Tory MP — had been asked to reply to the fund manager in her own name.