CALLS for Iain Duncan Smith to resign today overshadowed the Conservative leader's solid showing in a crucial poll test.

Senior MP Crispin Blunt deserted the front bench last night, saying Mr Duncan Smith must go, whatever the local election result.

Tory gains were overshadowed by his warning that Mr Duncan Smith was a "handicap" who would keep the party out of power.

The dramatic attack enraged Mr Duncan Smith's supporters on a night which produced signs of Conservative recovery.

The party seized control of a swathe of councils after gaining more than 500 seats.

Liberal Democrats were set for an historic strong showing as Tony Blair's "Baghdad bounce" poll rise in the wake of war with Iraq failed to protect Labour.

But Mr Blunt's dramatic exit forced Conservatives to once again defend their leader instead of focusing solely on their gains.

Former leadership rival David Davis was among the senior party figures who insisted: "There is not going to be a challenge." However, Labour and the Liberal Democrats said it showed the "knives are out" for the Tory leader.

Mr Blunt, the Tories' second-in-command on trade and industry, timed his announcement to cause maximum damage as polls closed.

"Whatever the headline results in today's local elections, the fact is the Conservative Party is making no real progress," he said last night.

"We carry the handicap of a leader whom Conservatives in Parliament and outside feel unable to present to the electorate as a credible alternative Prime Minister.

"He has failed to make the necessary impact on the electorate and I don't see any prospect of him doing so."

Mr Blunt added: "If we are a political party that is serious about regaining power, our leader has to now be replaced."

It was the latest in a series of damaging episodes Mr Duncan Smith hoped to put behind him.

Supporters hoped a strong showing would end speculation over his leadership.