Michael Portillo's hopes of becoming Tory leader suffered a double setback last night as Iain Duncan Smith overtook him as the front-runner in the race to succeed William Hague.
David Davis, the former minister for Europe, pulled out of the contest yesterday and threw his weight behind Mr Duncan Smith, appealing to the 17 other MPs who had backed him to follow suit.
The Portillo campaign will hit more trouble tomorrow night when a video diary made by Amanda Platell, the Tories' former head of news and media, is screened by Channel 4. It includes claims that allies of Mr Portillo and Francis Maude, the shadow Foreign Secretary and his campaign manager, undermined Mr Hague during the general election in an attempt to further Mr Portillo's leadership ambitions.
Although Ms Platell's criticism is directed at "Portillo's people" rather than him personally, the timing of her disclosures is bound to raise further questions about the shadow Chancellor's judgment. One source told The Independent: "The programme shows the point in the general election campaign when Portillo's supporters turned and started briefing against Hague."
The bookmaker Ladbrokes installed Mr Duncan Smith as even-money favourite for the first time after Mr Davis bowed to the inevitable and withdrew from the race. Mr Portillo, Ladbrokes' favourite to be the next Tory leader since betting began two years ago, saw his odds lengthen from evens to 6-4, with Kenneth Clarke on 3-1.
Last night the betting among many Tory MPs was that Mr Portillo could be eliminated from the contest on Tuesday to choose the two names to go into the decisive ballot of the party's 300,000 members. The result will be announced on 12 September.
Mr Portillo's problem is that he may struggle to win more than three or four votes from the 35 MPs who backed Mr Davis or Michael Ancram in Thursday's re-run first round. Up to 12 of the 18 MPs who backed Mr Davis are expected to switch to Mr Duncan Smith, with up to six voting for Mr Clarke.
Meanwhile, at least half of the 17 MPs who supported Mr Ancram are expected to back Mr Clarke, with the remainder more likely to rally behind Mr Duncan Smith than Mr Portillo.
A nail-biting vote is in prospect on Tuesday. Unofficial estimates circulating among Tory MPs last night predicted that Mr Duncan Smith will top the poll with 58 votes, ahead of Mr Clarke on 55, with Mr Portillo trailing in third place on 53.
Such a close result would inevitably provoke demands for all three men to go into the members' ballot, although that is likely to be deemed illegal under the party's rules.
As the three candidates prepared for a frantic round of campaigning before Tuesday's ballot, Mr Portillo insisted he was the "unity candidate". He said: "I believe I am the least factional of the candidates and we have to make factions completely a thing of the past."
Mr Duncan Smith told reporters: "There's another round to go, we can't take anything for granted."
Mr Clarke said he was "on course to come second" in Tuesday's vote. He paid tribute to Mr Davis, describing him as a "great political figure", who was "going to be a very big man in the Conservative Party".
Mr Davis admitted he could not bridge the gap with the three main candidates after failing to win over Mr Ancram's backers. He said Mr Duncan Smith was "the candidate most likely to carry forward the agenda I have set out".
The rival camps launched an attempt to stop the Duncan Smith bandwagon, saying he undermined John Major's government by rebelling against the Maastricht treaty.
Steven Norris, a close ally of Mr Portillo and a Tory vice-chairman, said: "From the pronouncements he has made, those right-wing views are not views that many decent people would want to be associated with."
John Maples, who is backing Mr Clarke, said: "Iain is a charming and honourable guy, but his brand of conservatism is a rather old-fashioned one."
As they spend this weekend in their constituencies, some Tory MPs may come under pressure from local activists to scupper Mr Portillo's chances. "There is a strong groundswell against Portillo in the grassroots," said one rival.