The junior defence minister Tom Watson and a string of junior members of the Government today quit their posts in an attempt to force Tony Blair to step down or name a date for his departure.
In what appeared a concerted move, the resignations came within hours of each other today - starting with Mr Watson shortly after 11am.
His resignation brought a ferocious outburst from Mr Blair, who branded him "disloyal, discourteous and wrong" for signing up to a round-robin letter demanding the Prime Minister stand down.
Parliamentary Private Secretaries Khalid Mahmood, Wayne David, Ian Lucas, Mark Tami, David Wright and Chris Mole then also publicly renounced their jobs.
Mr Blair branded Mr Watson "disloyal, discourteous and wrong". Within minutes of Mr Watson announcing his resignation, Mr Blair said he had been planning to fire him anyway.
Mr Blair said in a statement to the Press Association: "I have heard from the media that Tom Watson has resigned. I had been intending to dismiss him but wanted to extend to him the courtesy of speaking to him first. Had he come to me privately and expressed his view about the leadership, that would have been one thing.
"But to sign a round robin letter which was then leaked to the press was disloyal, discourteous and wrong. It would therefore have been impossible for him to remain in Government."
In a reply to Mr Watson's letter of resignation, Mr Blair warned that efforts to force him to name a date for his departure were harming the party and were "divisive... and totally unnecessary".
The best way of securing future election victories was "through setting out the policy agenda for the future combined with a stable and orderly transition that leaves ample time for the next Leader to bed in", he said.
Raising the spectre of Labour's 18 years in opposition - caused in part by the public perception that the party was disunited - Mr Blair warned: "We are three years from the next Election. We have a strong policy platform. There is no fundamental ideological divide in the Labour Party for the first time in 100 years of history. For the first time ever, we have the prospect not just of two but three successive full terms.
"To put all this at risk in this way is simply not a sensible, mature or intelligent way of conducting ourselves if we want to remain a governing party."
Conservative leader David Cameron said the Labour Government was in "meltdown" and Mr Blair was a "lame duck".
Speaking in New Delhi during a week-long trip to India, Mr Cameron told the Press Association: "I'm here in India to face the challenges of the future and increasingly it appears this Government is in meltdown and divided.
"It seems unable to show leadership on the challenges of the future."
In a letter to Mr Blair tendering his resignation this morning, Mr Watson wrote: "It is with the greatest sadness that I have to say that I no longer believe that your remaining in office is in the interest of either the party or the country.
"How and why this situation has arisen no longer matters. I share the view of the overwhelming majority of the party and the country that the only way the party and the Government can renew itself in office is urgently to renew its leadership."
About 90 minutes later, Mr Mahmood stood down as Parliamentary Private Secretary to Home Office minister Tony McNulty.
This was followed shortly by a joint statement from Mr David (MP for Caerphilly), Mr Lucas (Wrexham), Mr Tami (Alyn and Deeside) and Mr Wright (Telford), announcing their decision to leave their PPS posts.
The four said that Mr Blair's failure to end the uncertainty over when he would leave office was "damaging the Government and the party".
It was not enough for Mr Blair to indicate, through close allies, that he was planning to quit within 12 months, they wrote, adding: "We have vitally important Scottish Parliament, Welsh Assembly and English local authority elections next year and we must resolve this matter well in advance of these."
Chris Mole, PPS to communities minister Phil Woolas, later added his name to the list of those resigning.
A report in The Sun today claimed that Mr Blair would stand down as Labour leader on May 31 next year and finally leave office on July 26 2007 after an eight-week contest to choose his successor - expected to be Chancellor Gordon Brown.
But a close ally of Mr Brown, former minister Doug Henderson, today said he could not think of a worse date for the transition of power, coming as it does three weeks after the Scottish, Welsh and local elections.
Blair should announce his resignation this autumn, giving the new leader plenty of time to set out his stall ahead of the May polls, said Mr Henderson.
He said on BBC Radio 4's World at One: "I think people, when they vote next May, will want to know what the Labour Party will do in the future, not what it has done in the past.
"I think they will want to see a new leader in place by then, so people can judge the Labour Party in a forward way rather than looking at the legacy of what we have done over the last nine years."
The "sensible" position was for Mr Blair to quit "some time in the autumn, to allow an election to take place to appoint a new leader of the Labour Party either in the very late autumn this year or the very early spring, so that a new leader is in place by March next year, so that leader can set out the stall well in advance of the local elections and Scottish and Welsh elections", he said.
Today's resignations will have all the more impact as all seven of those quitting are known as New Labour loyalists who have previously been ready to support Mr Blair to the hilt.
In particular, Mr Watson previously served as a Government whip and was expected to rise through the ministerial ranks under the Prime Minister.
The West Bromwich East MP said he was warned last night by Chief Whip Jacqui Smith that his position as a Government minister would be "untenable" unless he withdrew his name from the letter signed by him and other MPs elected in 2001.
"I have reflected on this overnight," he wrote. "I cannot withdraw my name, and therefore I accept her judgement.
"I do not believe that statements so far give us the clarity necessary to progress over the next year.
"Nor do I believe that newspaper reports of potential dates which may have appeared since I signed the 2001 intake's letter can provide the clarity the party and the country so desperately need.
"It is with the greatest regret, therefore, that I must leave the Government."
Mr Blair's official spokesman said of The Sun story: "We are not going to give a running commentary on things. That applied yesterday to The Sun as well. People may contact us with dates but we are not going to comment.
"The suggestion that this was in some way an authorised No 10 operation is wrong."
Mr Mahmood, MP for Birmingham Perry Barr, said in his letter to Mr Blair: "The party and the Labour Government's work is more important than any individual. Sadly, I feel that your remaining in office no longer serves the best interests of the party or the country.
"Given which views, it is with the greatest regret that I must leave the government."
Downing Street said transport minister Derek Twigg would replace Mr Watson as veterans minister, and Tom Harris, MP for Glasgow South and previously PPS to Health Secretary Patricia Hewitt, would become a transport minister.
One of Mr Blair's most vocal critics called today for him to be given "space" to implement his apparent resignation timetable.
Following the report of a May 31 resignation, ex-minister Glenda Jackson said: "This may not have come out in the most ideal way but we have been calling for a timetable, we now have a timetable and it is only fair to give the Prime Minister the space to implement that timetable in consultation with the party and any potential successors."
Mr Blair's closest political friend, his agent John Burton, said he had no knowledge of a timetable, but called for a contest to succeed Mr Blair, rather than a coronation of Chancellor Gordon Brown.
Mr Burton said Mr Blair backed such a contest and the premiership would not simply be handed down to "the heir apparent".
He told BBC Radio 4's Today programme that he had "no indication whatsoever" if Mr Blair had decided on a timetable.
Liberal Democrat leader Sir Menzies Campbell said: "This is no longer a matter of the convenience of the Labour Party and the ambitions of its senior members. What is at issue is the national interest, which is not being served by the continuing uncertainty over Mr Blair.
"The Labour Party has created this situation and has the responsibility to solve it. Mr Blair should either resign or state a date."
Following is the full text of the letter from Tom Watson, to Tony Blair:
The Labour Party has been my life since I was 15 years old. I have served the Party at every conceivable level and your own leadership since 1994 in a dozen different capacities, latterly as MP for West Bromwich East, a Government Whip, and as Parliamentary Under-Secretary of State at the Ministry of Defence. My loyalty to you personally, as well as to the Party and the values we stand for, has been absolute and unswerving. The struggle to fashion the kind of credible, convincing, effective Labour Party you now lead has been the preoccupation of my adult years.
My pride in what our government has achieved under your leadership is beyond expression. We have revolutionised the lives and expectations of millions of our citizens, combining social justice with prosperity in a way which is unprecedented in the history of our country. Your leadership has been visionary and remarkable. The party and the nation owes you an incalculable debt.
So it is with the greatest sadness that I have to say that I no longer believe that your remaining in office is in the interest of either the party or the country. How and why this situation has arisen no longer matters. I share the view of the overwhelming majority of the party and the country that the only way the Party and the Government can renew itself in office is urgently to renew its leadership.
For the sake of the legacy you have long said is the only one that matters - a renewed Labour party re-elected at the next general election - I urge you to reconsider your determination to remain in office.
As you know, I had a conversation with the Chief Whip last night, in which she asked me to withdraw my support from the 2001 intake's letter calling on you to stand down, or my position would be untenable as a government minister. I have reflected on this overnight. I cannot withdraw my name, and therefore I accept her judgement.
I do not believe that statements so far give us the clarity necessary to progress over the next year. Nor do I believe that newspaper reports of potential dates which may have appeared since I signed the 2001 intake's letter can provide the clarity the party and the country so desperately need.
It is with the greatest regret, therefore, that I must leave the Government.
Tom Watson MP
West Bromwich East
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