Exit the Quiet Man, quietly. Now the stage is set for Howard

Michael Howard became the overwhelming favourite to lead the Conservative Party last night after Iain Duncan Smith's brief reign was brought to an end by his MPs.

Having spent little more than two years in the post, Mr Duncan Smith resigned within minutes of the announcement that he had lost a motion of confidence by 90 votes to 75.

David Davis, the shadow Deputy Prime Minister and a possible contender, cleared the way for Mr Howard when he announced that he would not be running. Mr Howard, the shadow Chancellor, is expected to launch his candidacy today and huge pressure will be put on other hopefuls to ensure a "coronation" rather than a lengthy leadership contest.

Speaking on the steps of Conservative Central Office, Mr Duncan Smith said "the parliamentary party has spoken" before stating that he would remain as acting leader until a successor had been chosen. "I will give that new leader my absolute loyalty and support. I will not publicly choose between the candidates in the coming election," he said.

"Although I will not be the prime minister of the first Conservative government of the 21st century, I believe I have provided its policy agenda."

The broad coalition backing Mr Howard was underlined when Liam Fox, the shadow Health Secretary, Oliver Letwin, the shadow Home Secretary, and Stephen Dorrell, a former health secretary, announced their support for him last night. Dr Fox said: "I think it is self-evident that he is a man with enormous experience, he is a political heavyweight, we don't need to wonder whether he will be able to carry out his duties as leader effectively, and we certainly know that he can land a few blows on Tony Blair because he has done so in more than one office of state in the past."

In a statement, Mr Davis made clear that he saw himself as a leader-in-waiting when he declared his support for Mr Howard. "A large number of colleagues have encouraged me to put my name forward as next leader of Conservative Party, more than enough to lead me to believe I would win such a contest in Parliament and in the country," he said.

"But in recent years, our party has had a terrible time with splits and divisions, infighting and factionalism. This has greatly damaged our ability to take the fight to this appalling Labour Government.

"I am concerned that a protracted battle over the leadership will create still more divisions and that the aftermath of a contest will create serious difficulties for us in the run-up to the next general election."

Mr Davis finally met Mr Howard at 6.30pm and told him that he would not stand.

Several MPs loyal to Mr Duncan Smith condemned the way he had been overthrown as leader and Ann Widdecombe, a former minister, attacked the "unseemly haste" of the expected deal between Mr Davis and Mr Howard. Sir Teddy Taylor, MP for Rochford and Southend East, said the campaign to unseat Mr Duncan Smith had been "despicable and cowardly".

But Crispin Blunt, MP for Reigate and the first to call for the leader to go, said the vote showed that the Conservatives were "serious about getting back into power". David Curry, MP for Skipton and Ripon, said: "It's a necessary outcome once somebody has lost authority you can't get it back."

Sir Michael Spicer, chairman of the backbench 1922 Committee, announced the result of the vote of confidence and said that nominations for the post of leader would have to be submitted by 6 November, with the first ballot of MPs on 11 November. Mr Duncan Smith will remain as acting leader until a replacement is found.

An embryonic campaign for Mr Howard had already started even before the result was announced. Such a so-called coronation for Mr Howard would depend on no other candidates standing, but would ensure that a new leader could be in place swiftly without the division of a full-blown contest.

With Michael Portillo and Kenneth Clarke expected not to run, the other possible candidates were Michael Ancram, the shadow Foreign Secretary and Tim Yeo, the shadow Trade and Industry Secretary. Mr Ancram was said to be considering his position last night.

Earlier, Mr Duncan Smith had made a final attempt to persuade his colleagues to back him, pleading with them to end a decade of bitterness and division within the party. In a 20-minute address to the 1922 Committee, he admitted that he had made mistakes ­ but said any new leader would have to go through the same learning curve. There was no "white knight" who could come charging to the rescue and win the next general election, he said.