Tony Blair is expected to outline his plans for leaving office after a wave of resignations from the government.
Tony Blair is expected to confirm later he will be stepping down as prime minister within the next 12 months.
It is thought he will confirm what friends have said - that he will leave office by the time of the party conference in autumn 2007.
Commons leader Jack Straw said voters expected Mr Blair to stay "to the halfway point of a normal four-year parliament", which would be May.
Former Home Secretary David Blunkett has told Gordon Brown's allies to stop trying to make Mr Blair quit now.
It follows 48 hours of feuding which saw eight government members quit over Mr Blair's continued leadership.
The plea came as Mr Blair suffered the resignation of eight junior members of the government over his leadership.
Downing Street denied reports Mr Blair would step down earlier than May to give a new leader a chance to bed in.
BBC political editor Nick Robinson said Mr Blair and Mr Brown had had an "acrimonious meeting" during the day, and that a close friend had indicated the chemistry between them had now collapsed.
Mr Blair and Chancellor Gordon Brown were said to have to have had an "acrimonious meeting" over Labour's future on Wednesday morning.
It was followed by a day of open warfare between supporters of the chancellor and Mr Blair over when the prime minister should quit.
Earlier, Mr Blair branded ex-junior minister Tom Watson, the most senior person to quit, "disloyal, discourteous and wrong" for signing a letter urging him to go.
Mr Watson and seven parliamentary private secretaries (PPSs) - who are unpaid ministerial aides at the bottom rung of the government ladder - were among a number of normally loyal Labour MPs from the 2001 intake who signed a letter calling on Mr Blair to quit.
Speaking on BBC Radio 4's Today programme, Mr Straw said he believed the prime minister had provided "sufficient certainty for the party to settle down, to draw back from this abyss" at the end of an "unsatisfactory" few days.
The seven were: Khalid Mahmood, Wayne David, Ian Lucas, Mark Tami, Chris Mole, David Wright and Iain Wright.
Mr Blair had "made it clear - or it has been made clear on his behalf - this forthcoming conference, in three weeks' time, will be his last annual conference", he told BBC Radio 4's Today programme.
Uncertainty
"There has to be another leader in place by next year's annual conference.
In a joint statement, four of the PPS group said Mr Blair had "not ended the uncertainty over when you intend to leave office, which is damaging the government and the party".
"Our procedures take some time, because we're a democratic party," he said.
GOVERNMENT HIERARCHY Cabinet: 23 people - appointed by PM to head departments and decide government policyMinister of State: 28 people - middle-ranking ministers responsible for specific areaParliamentary Secretaries/ Under secretaries of state: 36 people - the most junior ministers, often responsible for aspect of department's work Whips: 23 people - communicate government objectives and MPs' concerns Law Officers: 3 people - provide high-grade legal adviceParliamentary Private Secretaries: 55 people - act as unpaid assistant to minister. Seen as first rung on ladder
"There has to be some certainty about who the leader is before the summer break next summer, not afterwards, and people can then work backwards from there.
Iain Wright, PPS in the Department of Health, and a hand-picked replacement for the safe seat of Hartlepool formerly held by Peter Mandelson, said he "believed that the party and the government cannot renew itself in office without urgently renewing the leadership".
"I think that is satisfactory. I think it's what the party accepts."
Gordon Brown's backers say that assurances Mr Blair will resign in May are "not enough", but deny that the chancellor is plotting against the PM.
Junior defence minister Tom Watson and seven government aides - or Parliamentary Private Secretaries - resigned on Wednesday after urging Mr Blair to stand down.
But Mr Blair's supporters claim the calls for him to quit are an orchestrated plot by supporters of Mr Brown.
Mr Blair branded Mr Watson, the most senior person to quit, "disloyal, discourteous and wrong" for signing the letter.
Mr Brown has so far declined to comment on the furore.
An ally of the chancellor denied the eight resignations were part of a plot by the Brown camp.
Mr Blunkett says the dissidents should "step back from the brink" and back off to avoid a split in the party.
HAVE YOUR SAY I think Mr Blair is left with no option but to lay out a clear timetable for departure Mark Thomas, Hastings Send us your comments
Also on Wednesday, it emerged that environment secretary and potential deputy leadership candidate David Miliband had told the New Statesman magazine no other Cabinet ministers should challenge Mr Brown for the leadership.
Mr Miliband also confirms reports that he was "seriously worried" about Mr Blair's refusal to call for an immediate ceasefire in Lebanon last month.
