Ken Clarke says his laid back attitude appeals to voters

The ex-chancellor told a fringe meeting at the Tory conference he did not want to become prime minister just to see the whole thing "explode" in his face.

Mr Clarke insisted his team would be filled with Eurosceptics and there was no secret plot to convert them.

Rival Liam Fox later said the UK should be ready to withdraw from the EU if the price of membership become too high.

Dr Fox told a conference fringe meeting: "I think our political weakness has been our lack of courage in defining what price we are not willing to pay for European membership."

Opposition warning

His words came as Mr Clarke warned Tory members the party would lose the next three or four elections if it allowed Europe to dominate their choice of leader.

Mr Clarke's European views which were widely blamed for costing him the leadership in 2001.

He told the Independent newspaper's fringe meeting the party would remain in opposition for decades if it continued to let Europe dominate its choice of leader.

Mr Clarke said the party must end "civil war" on the issue.

The single currency and European agenda were now "completely off the agenda", he said. Instead, economic reform had to be the focus of debate about the European Union.

Mr Clarke tried to allay fears about how a Europhile could lead a Eurosceptic party.

The party did have "wounds" on Europe, he said.

But he argued: "I know my colleagues in Parliament let alone the voluntary party well enough to know that any secret plot I have to turn the whole lot back into europhiles is rather a tall order.

"If you think I have gone through all this process to try and become prime minister in four years' time to see the whole blasted thing exploded when I destroy my political base by trying to take us into the single currency I can only assure you that is a paranoid fear."

Donor unimpressed

Mr Clarke was asked what he would do if Tony Blair and Gordon Brown proposed European ideas which he backed but his party opposed.

But the Rushcliffe MP insisted that was not going to happen.

"Tony Blair wishes to talk about anything else - a bit like me," he said.

His comments about Europe failed to win over major Tory donor Sir Stuart Wheeler, who has said he would hesitate to bankroll a Clarke-led party because of his European views.

"I am not reassured," Sir Stuart told BBC News.

The betting tycoon likened Mr Clarke to Tony Blair - they had both wanted the euro and the constitution and now accepted only that both were out of the question at the moment.

He warned that much of the constitution could be introduced "by stealth", adding: "Clarke would be in favour of all of that."

Hamlet comparison

The fringe meeting also saw Mr Clarke discuss why he was popular in the opinion polls.

He said that one danger was that he was almost too laid back, with some people imagining him being like the man in the Hamlet adverts who just lit up a cigar when disaster struck.

"It has saved me from ever suffering what I have seen finish off political career after political career: I do not suffer from stress."

Mr Clarke said the Tories would be in "terrible, terrible trouble" if it lost again and started settling down to being a right-wing party of opposition.

It was absurd that only 31% of women voters had backed the Conservatives at the last election, he said.

The party was perceived as too hard line and did not look interested in issues such as the economy, health, education and childcare.

"That cost us a lot of young and - I fear - probably young, educated, aspirational women," he argued.

Mr Clarke also raised fears the lengthy leadership contest was giving the government a "free run".

And he said he would have preferred MPs to have the final say on choice of leader as Tory members could be "too partisan" and criticise some of the contenders.