By Nick Assinder
Political correspondent, BBC News website
So how will Tony Blair's reign in Downing Street end?
Will it be on a wave of euphoria after a decade in power, with "Blairism" irrevocably embedded into the Labour party and society and voters demanding he stays on?
Tony Blair wants an orderly exit from Downing Street
Or will he be forced out by his own party, in the manner of Margaret Thatcher, in a brutal coup by those who believe he has become a dangerous liability, out of touch with both Labour and the public?
With a pivotal party conference just three weeks away, these are two rival scenarios being presented to delegates and grassroots members.
On the one hand there is a leaked memo, said to come from senior Downing Street aides, which sets out a typically detailed and tightly-controlled programme to take the prime minister into his retirement.
"As TB enters his final phase he needs to be focusing way beyond the finishing line, not looking at it.
"He needs to go with the crowds wanting more. He should be the star who won't even play that last encore," it states.
That is the process the prime minister already appears to be engaged in, with forward-looking speeches around Britain on social exclusion and other issues planned for the coming weeks.
And loyalist cabinet minister David Miliband has added to that impression by stating he believes the "conventional wisdom", that Mr Blair will go in about 12 months' time, is "reasonable".
Then, however, there is the alternative view - the "Thatcher scenario", which Mr Blair and his aides want to avoid at all cost.
Miliband suggested Blair has another year
There are said to be at least two letters to Mr Blair being drafted by 2001 and 2005 intakes of Labour MPs, led by normally loyal MPs, urging him to resign sooner rather than later - one of which has actually been sent.
They appear to have been provoked by the prime minister's insistence in a Times interview last week that he had no intention of using the Manchester conference to give a more detailed timetable for his departure.
There are also motions planned for the conference demanding a timetable for his departure.
And if he still refuses, the question is being raised of whether Chancellor Gordon Brown and his supporters will finally be prompted to move against him.
What this all boils down to is a familiar struggle by a prime minister determined to keep control of his own future and ensure he leaves on a high while events threaten to tear that control from his hands and overwhelm him.
Those urging him to go soon, however, believe the moment at which he can go while still at the top of his game has long passed and that things can only get worse for him from here on.
The Conservative Party appears to be developing a consistent lead in the opinion polls and there are many in the Labour Party who want to get on with the job of putting Mr Brown into 10 Downing Street to tackle its leader, David Cameron.
Downing Street is insisting the memo was not seen by the prime minister or senior officials.
But it will be seen by some as evidence the prime minister and his allies are focusing their energy on his exit strategy rather than the job of government.
That will sting, as only last week Mr Blair was telling his party to stop "obsessing" over his future. Those comments appear to have had the opposite effect.
And, if Mr Miliband's suggestion Mr Blair would be gone within a year was supposed to calm affairs it has probably failed too.
There is also the suspicion that one of the reasons the prime minister may want to delay his departure is to ensure there is a credible, Blairite alternative on offer to challenge Mr Brown for the leadership.
The prime minister is resolutely attempting not to be distracted by all this movement and to be "getting on with the job".
But it is hard to escape the feeling that, this time, things may indeed be running ahead of him.