Iain Duncan Smith last night lost a vote of no confidence in his leadership.

In a packed corridor above the Commons chamber, Sir Michael Spicer announced the end of Duncan Smith's career as Tory leader.

MPs voted by 90 to 75 to sack Duncan Smith just two years after he succeeded William Hague.

Michael Howard now appears set to become Tory leader following what many expect to be a carefully crafted deal between all wings of the party.

Speaking on the steps of Central Office, Duncan Smith conceded defeat and pledged loyalty to his successor.

"We've had a lot of words over the last few days," he said. "This is not a time for many more."

"The parliamentary party has spoken - and I will stand down as leader when a successor has 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."

The Chingford MP will remain as a caretaker leader until his successor is chosen.

Sir Michael said the first round of voting will take place on Tuesday, November 11.

The outgoing Tory leader paid tribute to his staff and thanked his family for their support.

"My deepest thanks to my Shadow Cabinet and front bench team, my parliamentary colleagues and all the staff of Central Office," he said.

"And most of all, to Betsy and my family, whose support in the last two years has been unfailing.

"It has been an immense honour to lead this great party - and to be the first leader elected by its membership."

And he said he hoped his successor would lead the Conservatives to victory.

Flanked by his Shadow Cabinet team, he added: "I profoundly hope that the next leader to be elected... will also be the next prime minister."

MPs paid tribute to Duncan Smith after he announced his resignation.

Angela Browning said the result was far from a humiliation for a decent leader.

Geoffrey Clifton Brown said the party should "thank Iain".

"He has done a great service to the party, bringing us from catastrophic defeat to level pegging with the government," he said.

"It is now time to move on. I would like to see a coronation between Michael Howard and David Davis."

Crispin Blunt, who was first to call for Duncan Smith's resignation, said the Tories could now focus on making progress against the government.

"It is a sad and serious moment but it is an evening when the Conservative Party became serious about the next general election," he said.

David Curry said: "I'm glad he has had a good score. It wouldn't have helped if the party had been humiliated."

Former Asda boss Archie Norman, who had been critical of Duncan Smith's leadership, said he had relinquished office with "dignity".

"Iain came into the job with a reputation for integrity and he will leave in the same fashion. He moved the party on a long way," he said.

Derek Conway, a key player in attempts to remove Duncan Smith, said: "This is a sad but necessary conclusion. The Conservative Party needs a winner."

Duncan Smith's dismissal came after a day of intense rumour and intrigue around Westminster. But it also sets the scene for a bitter exchange between the parliamentary party and its supporters in country.

Voting was swift, with two thirds of the parliamentary party having voted in the first hour. The ballot opened at 3.30pm with former chancellor Ken Clarke and former shadow agriculture minister Ann Winterton among the first to cast their votes.

The Conservative leader, who had earlier made a passionate plea to his colleagues, voted shortly before 4.00pm.

Emerging from the committee room, he announced: "I did vote for myself."

The embattled leader had earlier addressed a packed meeting of the party's 1922 Committee.

Aides described the 25 minute speech as "blazingly honest" and "straight from the heart".

He arrived shortly after 2.30pm, describing his walk through the assembled media as "gladiatorial". He completed his address at 2.58pm - with many of his assembled colleagues thumping the table in support.

Whilst his speech won warm words it was not enough to restore confidence in his embattled leadership.

Over 120 journalists lined the corridor to catch snippets of the Tory leader's make-or-break address.

"We must end the bitterness that has tarnished our party, not just for two years but for the last 10 years," Duncan Smith said.

He also admitted to having "made mistakes" during his two years as leader. Emerging from the room, one senior Conservative MP described the speech as "very moving".

Edward Leigh said it was "the best speech he has ever made". Shadow defence secretary Bernard Jenkin added that he had delivered "a very passionate, very emotive, excellent speech".

But even Jenkin, a key lieutenant of the Tory leader, later refused to be drawn on which way the vote would go.

A former Cabinet minister said the Tory leader had "won himself quite a lot of credit" over the last three weeks.

But he had questioned whether the speech would be enough to address the lingering doubts about Duncan Smith's leadership..

The vote will lead to a bitter clash between the parliamentary party and the rank-and-file members.

Tory chairman Theresa May claimed rank-and-file members spent the day calling Central Office expressing astonishment at the moves to unseat Duncan Smith.

"They are saying 'We elected Iain Duncan Smith as leader'. They feel he was elected to take the party through to the next general election. They want him to be given the opportunity to do that," she said.

Grassroots supporters will now question why just 165 MPs have assassinated a man who won the support of 300,000 Tory voters just two years ago.