Conservative ex-chancellor Kenneth Clarke says he still has ambitions to one day become prime minister.

Mr Clarke also said he did not see why he should rule himself out as a successor to current Tory chief Iain Duncan Smith, to whom he lost in the final round of the party leadership contest.

Why should I rule myself out of the leadership of the Conservative Party? Kenneth Clarke

But he emphatically denied he had been given prior warning by Michael Heseltine of his call on Monday for the party to ditch Mr Duncan Smith.

Mr Clarke, speaking on Five News, said he had only known about Lord Heseltine's outburst when his wife had brought him the paper in bed.

"My reaction was to put the answer phone on," he quipped.

Questioned about his ambitions, the Rushcliffe MP insisted: "Of course I'd like to be prime minister of this country, but at the moment I don't see the political combination of circumstances that is going to allow me to do so.

"But I'm damned if I'm going to say, 'Oh well, I shall never do it now, I've decided to do something else'."

Runner up

But he stressed it was not helpful to his party or to himself to keep on raising the issue of a bid for the Tory leadership.

He repeated his "belief" that Mr Duncan Smith would fight the next election.

But he argued: "Certainly I share the general view which most Conservatives have, that the party has got to improve its performance in opposition to do better at the next election.

Iain Duncan Smith warned his party to "unite or die"

"But I don't think that means automatically, even in this celebrity, personality dominated world to another leadership contest."

He joked: "I have fought several of those - I'm the man who is usually runner up in the Conservative leadership elections."

But pressed on the issue, Mr Clarke said: "Why should I rule myself out of the leadership of the Conservative Party half way through my political career?"

'Christmas frivolity'

Mr Clarke said he had been "mildly" embarrassed about Lord Heseltine's outburst earlier this week.

Had he known of the former Henley MP's plans to speak in favour of him as the next Tory leader, he would have said: "Can't we leave it alone".

"I have got so used to being pursued about the leadership of the Conservative Party that this latest twist all seems to be Michael on a frolic of his own, enjoying himself before Christmas, and was merely a further irritation."

Heseltine can speak out because he's not in the main political arena, says Clarke

Lord Heseltine had claimed he was speaking for a "huge number" of former Conservative voters when he called for the party to oust Mr Duncan Smith.

The Tory former deputy prime minister dismissed furious calls from grassroots activists for him to be expelled from the party after he attacked Mr Duncan Smith in a newspaper interview.

Lord Heseltine repeated his claim that the party did not stand a "ghost of a chance" of winning the next election without a change of leader.

His comments were dismissed on Monday as "irrelevant" by Mr Duncan Smith.