London ? The future of Britain’s embattled opposition leader was in doubt Tuesday after Conservative Party rebels cleared the way for a vote of confidence that could lead to the removal of Iain Duncan Smith.

Enough lawmakers from the party had called for a vote to trigger the ballot, a Conservative Party spokesman said.

The announcement followed weeks of rumors of a plot to oust Duncan Smith, who has failed to make significant gains against Prime Minister Tony Blair’s governing Labor Party since being elected leader two years ago.

The spokesman, speaking on customary condition of anonymity, said Conservative Party official Sir Michael Spicer had received 25 requests from lawmakers urging a vote of confidence — enough to trigger a ballot.

If Duncan Smith fails to win a majority in the vote, an election for a new party leader will take place, and he will be excluded from running.

Rumors of a plot to oust Duncan Smith have swept through Parliament in recent weeks. Many Conservative lawmakers are angry the party is still trailing in the polls, despite a slump in Blair’s popularity and the troubles over the war in Iraq.

They fear that without a charismatic and powerful leader, the party has little hope of toppling the Labor Party and regaining power in national elections to take place in 2006.