The pressure on Tory leader Mr Iain Duncan Smith intensified last night as a second major donor to the party called for a leadership vote, writes Frank Millar in London.
Multi-millionaire businessman Mr John Madejski said the Conservatives needed a resolution to current uncertainty over Mr Duncan Smith's position and claimed an election would "clear the air".
Earlier Mr Duncan Smith insisted he will lead the country after the next election despite intense speculation that MPs are planning their strike against his leadership of the Conservative Party early next week.
The visibly-frustrated Tory leader had to fend off renewed questions about the threatened coup during a visit to Loughborough University, intended to focus on his challenge to the Labour government over top-up fees.
Trying his hand at cricket, Mr Duncan Smith vowed to "bowl out" Mr Tony Blair.
And he said: "This party will win the next election under my leadership.
"There is no question about my leadership. The question is who is going to lead the country after the next election? And I can tell you. It will be me."
However, Mr Duncan Smith implicitly acknowledged the growing challenge to his position on Wednesday night when he concluded a meeting of the shadow cabinet with the defiant message that he had earned the right to lead his party into the next election.
And chief whip Mr David Maclean's denial that he had told "IDS" he had lost the confidence of his MPs has failed to dampen reports that the Westminster whips fear the parliamentary party is out of control.
Usually reliable party sources said last night they now had no doubt that Mr Duncan Smith would face a no confidence vote, although they remained unsure as to the timing of the challenge.
The London Evening Standard has predicted it will come next Monday, with two senior backbenchers set to call for the requisite 25 letters from MPs to the chairman of the 1922 Committee, Sir Michael Spicer.
That prediction also coincided with indications that some MPs on the left of the party, loyal to former chancellor Mr Kenneth Clarke, may be preparing to join the leadership plot having previously resisted because of the absence of a credible and agreed alternative leader.
With the party awash with rumour and speculation, two senior MPs, Mr Derek Conway and Mr Crispin Blunt, yesterday appeared to differ only about whether Mr Duncan Smith would be gone before Christmas or within the week.
Mr Blunt - who quit the front-bench and called for a leadership challenge following the local elections last May - said a ballot was necessary to settle the issue.
"People who believe a change would be in the interests of the party are now in agreement with those who supported Iain that this issue must be resolved.
"The vast majority of the party want this issue to end. The only way it can end is a formal vote of confidence by the parliamentary party, so the logic is inescapable."
As former leader Mr William Hague led renewed attempts to rally support behind the leader, the former party chairman and now European Commissioner, Mr Chris Patten, said Mr Duncan Smith's previous position as a Maastricht rebel against prime minister Mr John Major made his position more difficult.
"Of course it's easier to preach loyalty if you practised loyalty," said Mr Patten. "That is as clear as daylight."
However, the Daily Telegraph maintained its studied neutrality telling Tory MPs merely to decide the issue once and for all.
In its editorial yesterday "the Torygraph" insisted: "For the good of the country, which sorely needs a strong Conservative leader, this baleful spectacle of an enfeebled leader struggling to control an unruly and querulous party must end one way or the other."