By Graham DinesPolitical EditorIAIN Duncan Smith's leadership of the Conservative Party is hanging by a thread today as he prepares to face a vote of confidence triggered by 25 MPs.

By Graham Dines

Political Editor

IAIN Duncan Smith's leadership of the Conservative Party is hanging by a thread today as he prepares to face a vote of confidence triggered by 25 MPs.

Members of the shadow cabinet were locked in a crisis meeting of several hours yesterday on their tactics for the vote as MPs gathered to discuss possible alternative candidates should IDS lose.

Putting a defiant gloss on the decision of 25 of his MPs to force him to submit to a ballot, Mr Duncan Smith said he welcomed the opportunity to win a "renewed mandate" to lead the party to the next election and end "this ludicrous leadership speculation."

He was immediately backed by a joint message of support from deputy leader Michael Ancram, shadow home secretary Oliver Letwin, party chairman Theresa May and shadow chancellor Michael Howard.

"Iain Duncan Smith is the duly elected leader of our party," they said: "He has faced considerable pressure over recent weeks and has done so with remarkable courage and dignity.

"He has said, and we agree with him, that he has earned the right to lead our party into the next election. He has healed the wounds on Europe. He has forged, for the first time in a decade, a radical and coherent programme of reform in the public services.

"He has once again made the Conservative Party the champion of the people and the advocate of choice and opportunity for all."

Speculation at Westminster was that even if Mr Duncan Smith garners enough support to see off the challenge, he may have to quit if he does not receive an overwhelming endorsement.

If he loses the vote, he will be forced to resign because under the rules of the Tory leadership election system, he is not allowed to stand again for 12 months.

The meeting of the 1922 Committee, the group of backbench MPs which will vote on IDS's future, has been brought forward to 2pm this afternoon. Mr Duncan Smith will address MPs shortly after it begins, probably at about 2.15pm and once the meeting closes the secret ballot on his leadership will begin.

The result is expected to be announced by Sir Michael Spicer, chairman of the 1922 Committee, at about 7pm.

Mr Duncan Smith became leader in September 2001 when he overwhelmingly defeated Kenneth Clarke. However, in the series of knock-out votes by Tory MPs, he received the backing only a third of MPs.

Jeremy Savage, the chairman of Norfolk and Suffolk Area Conservatives – the voluntary wing of the party – said he "regretted" the behaviours of MPs in forcing the ballot, which had severely damaged the image of the Tories.

Eric Flack, the chairman of Bury St Edmunds Conservative constituency association, said after watching IDS's statement: "He is a decent and honourable man. But I believe he is too badly damaged to win tonight."