"One senior figure said pressure will 'ratchet' up on the PM if Labour slips to third or fourth place.
He added: 'There is no person in the Cabinet ready to do the damage, it needs a stalking horse. But we are running out of time.'"
Like last summer, the signs are that none of the main candidates for the Labour leadership are willing to to bloody their hands over this. In which case, if Brown's going to be ousted, then it will require an intervention from a prominent backbencher. But who would be up for the task? I refer you to Matt's article from a few weeks ago, which suggested one probable name: Charles Clarke.