The findings directly contradict the former chancellor's key claim that he can lead the Tories to victory over a Labour Party led by Mr Brown at the next election.
Faced with a straight choice between Labour led by Mr Brown and the Tories led by Mr Clarke, 44 per cent of those interviewed said they would vote Labour and only 25 per cent said they would vote Conservative.
The poll will come as an unwelcome reverse for the Clarke camp, which had been boosted by a survey suggest- ing he has overtaken David Davis as the grassroots' favourite. Both frontrunners are secretly planning for a two-month campaign among activists.
IF YOU HAD TO CHOOSE...
At the next election....
Gordon Brown 44%
Ken Clarke 25%
At the last election....
Tony Blair 52%
Michael Howard 35%Reuse content