"I have informed the Prime Minister this morning that I will be standing as an Independent candidate in the election for Mayor of London. It is a decision I have taken not with joy, but with a heavy heart . . ."
If Ken Livingstone utters these words in the coming days, as so many within and outside the Labour Party wish him to, there will be uncomfortable times ahead for all concerned. Mr Livingstone will immediately be cast out of the party he has served for 30 years into an uncertain wilderness where the huge Millbank machine will ruthlessly pursue him.
If he brings party members and MPs with him, they too will feel the cold New Labour wind at their backs. And what of the cost to Mr Blair and his vision of a united party? Could he work with the populist maverick? Perhaps an Independent Livingstone is just what he wants?
The alternative for Mr Livingstone would be little better than his present circumstances. If he chooses to remain on the back benches, just as Tony Benn did in 1981 when he lost the Labour deputy leadership to Denis Healey, he will be another irritating reminder for Mr Blair of the Old Labour days. But he will be little more than that.
So Mr Livingstone faces a stark choice. Does he throw his hat into the ring and leave New Labour, or crawl back to mini-cult status on the back benches?
Three days after his defeat in the electoral college, he finally spoke out in typically belligerent style yesterday, accusing the Labour leadership of trying to "trample" on the wishes of Londoners. He steered clear of saying whether he would stand, but said that unless Labour dropped its plans for partial privatisation of the Tube, the mayoral election would be transformed into "a referendum on London's right to govern itself".
"The issues will be the following: will London have a transport system imposed on it that it does not want? Should London have a candidate imposed on it that it does not want? In other words, does London have the right to govern itself, or is devolution to be a charade?"
But, as Downing Street, the Deputy Prime Minister, John Prescott, and Frank Dobson have all reminded him this week, standing as an Independent would cast doubts on his sincerity.
Throughout the selection process for Labour candidates, Mr Livingstone repeatedly insisted that he would not stand as an Independent against a Labour nominee. On at least 18 occasions and in private letters to the Labour Party leadership, he pledged his support for party rules governing the selection process, whatever the outcome. In the London Evening Standard on July 30th last year, he said: "I am staying in the Labour Party. I am dying in the Labour Party." But there were also sufficiently vague statements in public and in private at least to raise doubts in the mind of the Labour leadership that he might, just might, cut loose from the party. Why else would the Guardian have run with a front-page story on Tuesday that the Cabinet minister, Mo Mowlam, was being lined up as a possible candidate to run against him if Frank Dobson was forced to stand down?
Downing Street denied the story. But in the words of one senior Labour figure quoted by the Guardian: "Politics is politics. If the polls tell a particular story, might he [Dobson] not have to look reality in the face?"
If Mr Livingstone calculates that the risk of standing as an Independent is worth taking, the immediate political fallout for Mr Blair will be uncomfortable. But it will not be disastrous. The Conservatives and the Liberal Democrats will claim once again that New Labour is falling apart, that it cannot control its MPs.
The Tory candidate, Steve Norris, will no doubt consider his campaign strengthened as Mr Livingstone struggles to sustain his popularity with diminished campaign resources.
But it is possible that Mr Blair would view Mr Livingstone's departure as the lancing of an annoying boil. The Labour leadership might well have to listen to his cries that the electoral college vote was "tainted". And if he wins the election, it will find itself having to work with a disruptive mayor. But after the euphoria of victory has passed, he will soon discover that he has little room for manoeuvre and the real power still resides at Downing Street.
Mayor Livingstone would make life difficult for Mr Blair. He would remind Londoners about the sorry state of funding for the Tube, he would demand answers to questions about the fall in numbers of police officers in the capital. But the Labour Party will not implode in the face of a Livingstone onslaught and Mr Blair and the Chancellor, Gordon Brown, will still control London's purse strings.