By Nick Assinder
Political correspondent, BBC News website
As Charles Clarke and Alan Milburn insisted many many times, the launch of their big policy debate website had absolutely nothing to do with the Labour leadership contest.
Mr Milburn insisted debate was not about Gordon Brown
Mr Clarke said there were two issues running side by side - the leadership and the future direction of the party.
"They are related but not the same thing," he declared, adding that he knew the notion was "counter-intuitive".
Or, as Alan Milburn put it: "That (the leadership) is not what this is about. End of story."
Except, of course, it was not and will not be the end of the story, as David Cameron proved only moments later during Question time.
The timing of the launch, the fact its very existence suggests a future leader needs to be given a policy road map rather than being allowed to impose a new direction, and the fact that the two men launching it are on record as having doubts about Gordon Brown had already ensured that, though.
As one of the journalists at the website launch put it - there is a very large elephant sitting right behind you, we all know it, why don't you just say it, you want a challenge to Gordon Brown.
That brought the assurance from Mr Milburn that Mr Brown had many commendable qualities, and from Mr Clarke that he still believed the chancellor would be the next leader - although neither ruled out standing against him, presumably, therefore as some sort of sacrificial lambs.
Mr Clarke has not ruled out a challenge
The particular elephant referred to, by the way, has a name. It is David Miliband.
Even though the two men appear absolutely genuine when they say their launch is nothing to do with the leadership - which does rather beg the question of why they have chosen to do it now - there is no doubt in anybody's mind in Westminster that anti-Brown factions are still desperately seeking another candidate.
Over the past year or so Alan Johnson, John Reid, even John Hutton have been mentioned. As, indeed, have Mr Clarke and Mr Milburn.
None of them seem overly eager to go for it and risk what most believe would be a certain, and probably heavy, defeat.
So the name now doing the rounds is that of the youthful environment secretary, Mr Miliband.
He has said he is "not a runner or a rider". Even some of his supporters - widely believed to include Tony Blair - believe this would be exactly the wrong time to risk it. They see him more likely as the next leader but one.
That attitude has helped the continuing sense in Westminster that Mr Brown is unstoppable - unless a substantial candidate steps forward.
Mr Cameron turned fire on Gordon Brown
Mr Milburn and Mr Clarke have long been arguing for a policy debate to "refresh Labour in power" and have been making weighty speeches of their own over recent months.
But there were some signs, despite their assurances, that they have concerns about Mr Brown and his style of leadership.
Mr Milburn spoke of the need for "a dialogue not a monologue".
He also said Labour would not achieve future success "on the basis of gratitude for past successes".
They also said future policy direction should be a matter for the whole party - and wider electorate - rather than "one person".
Both remarks were seen as thinly-veiled attacks on Mr Brown, who for understandable reasons appears to be keeping his plans under wraps ready for a 100 day blitz when he finally makes it to Number 10.
David Cameron needs no veils, of course, and was not about to let all this slide - another presumably unintended consequence of the launch.
He wanted to know why so many Labour figures who had worked with Gordon Brown thought he would make a terrible prime minister, but were not actually prepared to stand against him.
"The prime minister thinks he is Einstein but half his backbenchers think he is Mrs Rochester. Why not let him out of the attic and we can get on with the main event," he declared.
The prime minister was delighted to set out Mr Brown's economic record without actually endorsing him - unlike the slap down he was happy to deliver to declared left-wing candidate Michael Meacher.
Mr Meacher asked for an inquiry into private equity firms, only to be given a lecture on the need for a thriving economy and told there was no way he was going to be the next leader.
He can, presumably however, engage in the debate which everyone from the prime minister down appears to think is such a good idea.