Jacques Arnold resigned as a Parliamentary Private Secretary in the Home Office in order to back John Redwood. He said the Prime Minister "has proved unable to provide the inspiration and strong and determined leadership required in areas of mainstream concern".
Although Mr Arnold is a very junior member of the Government payroll, his defection comes soon after Lord Tebbit's endorsement of Mr Redwood.
But the signs that supporters of both Mr Heseltine and Mr Portillo plan to abstain from Tuesday's vote are more worrying for Mr Major. One rightwinger claimed that up to 100 MPs would fail to support either candidate in the first ballot, thereby intensifying the argument for Mr Major to stand down and allow others to enter the contest.
Mr Heseltine's supporters expect around 30 of their number to abstain in the hope of either forcing a second ballot or pressuring Mr Major to stand down. One said: "It is fairly clear. If you are keen on Michael, you have to abstain."
Mr Portillo's sympathisers are more divided. Some believe that they should leave Mr Major in place and allow their man to succeed shortly after a general election defeat.
Close advisers to Mr Portillo insisted that he, like Mr Heseltine, would be putting out no advice to supporters on how to vote. Both ministers have publicly backed Mr Major, and their henchmen have been instructed to keep a low profile.
But one Portillo-backer said that there was a late run for abstentions and that the result of MPs' individual assessments would be to say "a plague on both your houses" to Mr Major and Mr Redwood. That could reduce Mr Redwood's vote to around 50 and swell the abstentions to about 100, he said.
Another of Mr Major's fierce right-wing critics, who yesterday did a telephone trawl of back-bench opinion, believes the combined total of abstentions and votes for Mr Redwood "could be as high as 120". That would leave Mr Major with a "no man's land" victory. He would have the support of fewer than two-thirds of his MPs and fewer than half of his backbenchers.
Mr Redwood yesterday moved to head off the abstention threat to his campaign. On Radio 4's Today programme he urged Mr Heseltine's and Mr Portillo's supporters to vote for him. "The people they would like to see as leader did not come forward, so they have no choice but to vote for me," he said. Privately his backers hope his support is between 50 and 75 MPs.
Mr Major sought to bolster right wing support by hinting of more explicit support for a referendum on a single currency if he is re-elected. In an interview with the Financial Times he also cast Britain as the defender of the interests of countries outside a single currency. Mr Major's aides said, however, that he was not ruling out British participation in 1999 but is sceptical about the prospects of it going ahead.
A junior minister, who believes MPs are now "closing ranks" behind the Prime Minister, none the less conceded that in the event of a meltdown of support for Mr Major, Mr Heseltine would swiftly emerge as leader.
"I think Major will win," he said. "The only question is: will it be a big enough majority? If he gets over 200 votes he is probably OK, but not until 220-230 can you start to say he has achieved what he wanted."
Mr Major, however, is working on the reconstructed Cabinet that he would put in place after a victory.
Richard Ryder, the Chief Whip, will step down and probably leave politics at the next election. Mr Major wants to reward key members of his campaign team, such as Ian Lang, Secretary of State for Scotland, and Michael Howard, Home Secretary, both being considered for the Foreign Office.
Viscount Cranbourne, Leader of the Lords, and Brian Mawhinney, Secretary of State for Transport, would also be rewarded, and there is speculation that either could become Conservative Party chairman. One insider said: "The Prime Minister has not said to them, 'Brian, Ian, Robert, these are the jobs for you', but these chaps will be in a fairly strong position when it comes to jobs."
Alastair Goodlad, Minister of State at the Foreign Office and a former whip, is being tipped to take over from Mr Ryder. One minister said: "People are slightly in awe of him. He has an aura of fierceness you need in that job." An alternative candidate is David Davis, also a Foreign Office Minister of State.Reuse content