Speculation was mounting last night that the left-wing MP, Mr Ken Livingstone, might after all be barred from seeking Labour's nomination to run for Mayor of London.
After more than four hours' discussion at the party's London headquarters, the 13-member nomination board - which had earlier interviewed all four would-be-candidates - adjourned their deliberations without decision.
It was subsequently confirmed that the maverick MP and former leader of the Greater London Council had been invited back for further discussions tomorrow morning.
The news that the London Labour Party's "Livingstone nightmare" was likely to carry on came alongside the first polling evidence that the rows, divisions and accusations of mismanagement attending the mayoral race may be damaging the party nationally.
An ICM poll for this morning's Guardian suggests Labour's current lead over the Conservatives has dropped to an astonishing 10 percentage points.
While the poll was greeted with some surprise by Westminster commentators, one immediate conclusion being drawn was that voters might be reacting adversely to evidence of internal party divisions.
The ICM poll follows its findings yesterday that Mr Livingstone appears "unstoppable" in his attempt to become London Mayor - so long as his name appears on the ballot paper for the election next May.
Mr Livingstone last night expressed his astonishment at the board's failure to reach a decision. Speaking alongside his fellow candidates at a meeting at Friends House in London, he said: "I've seen Popes elected by Cardinals in a shorter time than this. It would seem to be a pretty simple choice, and I can't believe that it has taken them more than half an hour."
He went on: "In terms of Glenda [Jackson], Frank [Dobson], Ken [Baldry] and myself , I wouldn't have thought you would need much time to work out whether they are fit to stand or not."
Earlier in the day Mr Livingstone had maintained his consistent public confidence that it was "inconceivable" he would be denied the opportunity to put his case for selection to Labour's electoral college.
Extensive weekend briefing by 10 Downing Street had suggested the Prime Minister, Mr Blair, had finally decided to drop his opposition to allowing Mr Livingstone to join the race for the mayoralty - amid renewed allegations of "control freakery" and a refusal by the party centre to accept the logic of devolution.
Some sceptical observers, however, had distrusted the weekend briefing - suspecting a "spin" to distance Mr Blair from any decision by the nomination board to reject Mr Livingstone's candidacy.
And while Mr Livingstone entered yesterday's interview repeating his earlier pledge not to run as an independent, and offering to give any "loyalty pledge" demanded of him, an indication of potential trouble ahead came when he declared: "Whatever they ask I'll do it. As long as they don't privatise the tube."
This repetition of Mr Livingstone's long-declared opposition to any role for private finance in running the London Underground was a reminder that on one key issue at least he remains resolutely at odds with government policy.