Cameron: I put off making decisions

His frank acknowledgement comes in a new book by GQ magazine editor Dylan Jones who was given extended access to Mr Cameron over the period of a year.

"Sometimes maybe I put off making decisions that maybe I should have taken earlier," he said.

Elsewhere in the book, the Tory leader stresses just how important it is to be an effective decision-maker in government. "To make decisions in the long-term interests of the country you have to take quite tough decisions quite early on so that you can get things done within the life of a Parliament," he said.

Mr Cameron insisted, however, that he had learned a lot from the experiences of one of his predecessors as Tory leader, William Hague - including how to handle his shadow cabinet colleagues. "You appoint good people, and trust their decisions, but you have to know when to step in. William Hague has really helped me, because he made all the mistakes the first time round," he said.

He said he was convinced that he could have been in No 10 by now - although without an overall Commons majority - if Mr Brown had not abandoned his plans for a general election last autumn.

"I absolutely believe that if we'd have had that election that Gordon Brown would no longer have been Prime Minister and that the Conservatives would have been the largest party in a hung Parliament," he said. "Brown compounded calling off the election by then saying it was nothing to do with the polls, which was a massive mistake. It was a lie and it was treating people like fools."

The Tory leader admitted that it had been a huge gamble to deliver his first party conference speech as leader without notes - one that almost did not pay off. "It was a big roll of the dice to do it without any notes. No autocue, no funny business. There was a moment when I lost my train of thought, but no one really noticed," he said.

Not so clever was having his official driver follow him with his papers in the car while he cycled to and from work in the Commons, putting a dent in his "green" credentials. "I regret that my government driver took some of my papers home while I was on my bike," he said.

His aim in government, Mr Cameron said, would be to make his name as a social reformer, healing what he has called Britain's "broken society". "I'm going to be as radical a social reformer as Mrs Thatcher was an economic reformer, and radical social reform is what this country needs right now," he said.