Most of the electorate were elderly people who pay their subscription and never attend meetings and sent in a postal ballot after reading the Daily Telegraph. It was quite hard work getting their votes

Ken Clarke on the Tory leadership contest

"I think one of the biggest mistakes is Iain saying never to the single currency," Mr Clarke said.

"But I'm not wanting to go on the front bench and I'm perfectly absorbed in politics doing what I'm doing as a backbencher," he added.

Mr Clarke said the Conservatives would not find any stability until a referendum on the euro had decided the issue "one way or another".

Former leader William Hague's "extraordinary" Save the Pound campaign was the reason why the Conservatives lost so heavily in the general election, he went on.

"We would have lost anyway but no doubt it was made worse," Mr Clarke said.

Leadership result

Describing how he felt when he found out he had lost the Tory leadership contest, Mr Clarke said he was "disappointed", but not "totally surprised."

"Most of the (Tory leadership) electorate were elderly people who pay their subscription and never attend meetings and sent in a postal ballot after reading the Daily Telegraph.

"It was quite hard work getting their votes."

Commenting on reports of a rift between Tony Blair and Gordon Brown, Mr Clarke said tension between prime ministers and their chancellors was inevitable.

On his relationship with John Major, Mr Clarke said: "At times we irritated each other quite a bit - we were bound to," but, he added, they had remained friends throughout their period in office.