Barry Sheerman, once described as the leader of Labour's internal opposition, is at it again in the Independent  today, calling for Gordon Brown to resign. He writes:
No one would wish to underrate the significant contribution that Gordon Brown has made to our nation's politics. We all understand that, at heart, he wants the very best for Britain. However, now is the time for those around him who also care about our country's future to convince him that it is time for him to make way for a new leader.
All the evidence suggests that Brown's leadership reduces Labour support, that alternative leaders would improve our ratings, and that an election determined by voters' answers to the question "Do you want Gordon Brown to be Prime Minister for the next five years?" would further shrink Labour support.
The psephological case against Brown is a strong one. No prime minister has been as unpopular as him and gone on to win the subsequent election. A recent Times leader  revealed that Philip Gould has told the cabinet that Labour could win only if it replaced Brown.
This said, I'm rather sceptical of polls showing that Labour would do better under almost any alternative leader. To most voters, Harriet Harman and David Miliband are mere names. They don't know enough to dislike them.
The latest idea canvassed by the rebels is the so-called "Aznar option" . Under this scenario, Brown, like the former Spanish premier, would remain Prime Minister until the election but Labour would elect a new leader to fight the campaign.
Matthew Taylor, who first explored the possibility  back in August, points out:
In this way the internal contest within the party for its next leader is not about foisting a new prime minister on the country, but about choosing someone about whom the voters can make up their own mind.
The main stumbling block to any rebellion remains the absence of a definitive, Heseltine-type challenger to Brown. This is something of a pity, as the narrowing of the polls may actually strengthen the case for replacing Brown. In a hung parliament, a pluralist figure such as David Miliband would be far more likely to cut a deal with Nick Clegg than the tribal Brown.
History suggests that Sheerman and Clarke aren't likely to rouse a rebellion, but I'd be surprised if large parts of the PLP aren't considering all options as we enter 2010.