CHARLES CLARKE is ready to challenge Gordon Brown for the Labour leadership if David Miliband fails to mount a bid.

Confidants of the former home secretary say he will consider a leadership challenge to deprive the chancellor of a “coronation” for the top job if the environment secretary refuses to do so.

A bid by Clarke would force a debate on the future of the Labour party and leave Brown little choice but to flesh out where he stands. MPs fear that a coronation without a heavyweight challenge could make the party look undemocratic and go down badly with voters.

Yesterday Clarke told The Sunday Times he would not rule out a challenge to Brown and would “make a judgment” when Tony Blair announces his resignation, expected to be soon after the local, Scottish and Welsh elections on May 3. “I am not going to rule out under any circumstances running,” he said.

Those close to the former home secretary claim he will stand against Brown if Miliband refuses to join the race. “He intends to run a progressive campaign that will force a debate on the party’s future,” said one.

Clarke tried to make light of such talk yesterday, saying it was “very unlikely” he would stand. However, if he were to mount a challenge he insisted it would not simply be to provoke a policy debate within the party.

There would be little for Clarke to lose from a “kamikaze mission” and he is likely to be able to muster the necessary 44 Labour MPs to nominate him for the leadership. A gutsy bid by Clarke would be welcomed in many quarters as a chance to debate Labour’s future openly.

Clarke, along with the former health secretary Alan Milburn, recently launched a campaign calling for a debate on Labour’s “renewal” after 10 years in office. Their 2020 Vision website was seen by MPs as a potential launch pad for a leadership bid.

Clarke is said to believe that Miliband will not stand. Last week the 41-year-old environment secretary endorsed Brown more fully than before but failed to rule out a bid completely. MPs believe Miliband is merely positioning himself for a top job in a Brown government.

Yesterday Margaret Beckett, the foreign secretary, warned Miliband not to become a “human sacrifice” by standing. Peter Hain, the Northern Ireland secretary, warned that Blairites trying to stop Brown appeared to want David Cameron to take power.

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