The emails arrived at 10.24, and a day of political drama and intrigue began

The plot was hatched weeks ago and choreographed to explode in Gordon Brown's lap yesterday morning. But, as Andy McSmith and Nigel Morris explain, it was fatally flawed from the start

This was how the final plot to oust Gordon Brown began – not with a bang, but with a cock-up. At 10.24am yesterday, an email pinged into the computers of 350 Labour MPs – including members of the Cabinet – from plotter-in-chief Geoff Hoon.

At least one MP who saw the message was intrigued, because it was the first he had ever had from the former chief whip. But when he opened it, it was blank. At 10.58am, his curiosity was roused again by a second email from the same sender, but this one was as disappointing as the first. It said: "Apologies for sending a blank email earlier: it was obviously send [sic] in error! Mary Jo Bishop, Parliamentary Assistant, Geoff Hoon MP."

At 12.26pm, while most MPs were in the Commons debating chamber for the final few minutes of Prime Minister's Questions, a third email came from the same office: a 320-word message from Mr Hoon and the former health secretary, Patricia Hewitt, calling for a secret ballot that would allow MPs to deliver a verdict on Gordon Brown's leadership.

The email turned a snowbound Palace of Westminster into a hothouse of intrigue, with some Labour MPs coming out with furious denunciations of the plotters and others biding their time to see how the numbers stacked up, while from the Cabinet there was a long, curious silence.

Their explosive suggestion was that Labour MPs should sack a sitting prime minister, when the most likely date of a general election is only four months away. Their message did not put it in those blunt terms, but that was the subtext of their email, which called for a secret ballot that would "finally lay this matter to rest".

No British PM has been sacked this close to a general election in modern times. Had the plot succeeded, Gordon Brown would have chalked up several other historic firsts, none of which he would have wanted. He would have been the first prime minister to be brought down by an email, the first Labour leader to be sacked in the party's 110-year history, the shortest-serving prime minister since Alec Douglas-Home in 1964, and the first since George Canning, in 1827, not to lead his party into a general election.

The plot originated in a chance conversation soon after the Commons rose for Christmas. Hoon and Hewitt have offices on the same corridor in Portcullis House, across the road from Big Ben, and started discussing why the party was not getting its message over to people who would normally be thought of as Labour voters.

They agreed that the biggest problem was the Prime Minister's inability to communicate with potential supporters, and decided that when MPs returned in the new year, there should be a final attempt to force him out. The opening shots were fired by well-known enemies of Mr Brown – notably the veteran MP Barry Sheerman, who wrote a piece in The Independent on New Year's Eve, calling for his resignation. The same cry was taken up on blogs by Charles Clarke, the former home secretary, and Greg Pope, a former Labour whip.

The next, and most serious, was supposed to be the resignation of a Cabinet minister in the first week after MPs returned to the Commons, which the conspirators hoped would prompt other disillusioned ministers to walk out. Nick Brown, the Chief Whip and one of Gordon Brown's most steadfast allies, was worried enough by rumours of a plot to be overheard talking about it on a train, on a mobile phone, saying the parliamentary party was divided between "those who will soldier on" and "those who want him out". He need not have worried, because as one Labour MP scathingly remarked of the conspirators yesterday: "Such is their level of incompetence that they can't even plot properly."

Gordon Brown was warned about the Hoon-Hewitt email an hour or so before he went into the Commons chamber for his weekly confrontation with David Cameron. He left on a high, believing that he had worsted his Tory opponent. Instead of paying attention to protecting his career, Mr Brown went ahead with a private meeting in his office behind the Speaker's Chair with Mr Cameron and the Liberal Democrat leader, Nick Clegg, to brief them on the terror threat from Yemen.

Meanwhile, the few Labour MPs prepared to speak up for Hoon and Hewitt were drowned out by a chorus of backbenchers – including many critics of the Prime Minister – furious that they had convulsed the party at such an ill-chosen time.

Some of the emails sent privately to Mr Hoon – seen by The Independent – must have ruined his day. Lynne Jones, from the party's far-left, said: "As one of the few Labour MPs who did not nominate Gordon Brown as leader and am known not to be have been a great fan of his, I detect no deep division amongst colleagues or in the wider Labour movement about his leadership at the present time. I am therefore dismayed that you have given 'legs' to such a story."

Fellow left-winger Diane Abbott told Mr Hoon: "I can only assume that you have taken leave of your senses." Christine McCafferty, from Calder Valley, wrote: "I am appalled by your egocentric agenda and lack of judgement, at this critical time." The Reading MP Martin Salter added: "It is inappropriate for a former chief whip who is standing down at the next election to be advising hard-working and full-time Labour MPs on who would be best placed to secure a Labour victory."

Crucially, no Cabinet minister was prepared to throw away their last few months in office for a plot that might fail. On Monday, Westminster was awash with rumours that Tessa Jowell, a Blairite and an old friend of Hewitt, was on the verge of resigning – until she issued a public denial.

Without Cabinet support, the plotters were thwarted by Labour's rule-book, which makes it impossible for mavericks to mount a challenge to a sitting prime minister. Strictly, there needs to be a rival candidate with nominations from at least a fifth of the parliamentary party, or 70 MPs, and a vote by the Labour Party conference – which was held last autumn – before a contest can begin.

One former Cabinet minister calculated yesterday that if 100 Labour MPs wrote to the parliamentary party chairman, Tony Lloyd, supporting the call for a ballot, it would have to be held, and if Gordon Brown lost, he would have to step down. But the rebels were far short of that 100 figure.

Mr Lloyd had evidently made up his mind minutes after the news broke. There was a bizarre scene in Parliament's Central Lobby as Mr Hoon and Mr Lloyd stood almost side by side giving rival interviews to the TV cameras. Mr Lloyd's message was blunt: there would be no ballot because the plot lacked support. What is more, he pointed out, the rules did not allow it.

Mr Hoon was interrupted twice by angry backbenchers. Anne Snelgrove hissed "disgraceful" and Jim Sheridan heckled: "Loser!"

The noise from the backbenches was not matched by any immediate effort by Downing Street or the Cabinet to deal with the threatened uprising. Gordon Brown's entire team of professional spin doctors were seen in a Commons café at 2pm, calmly tucking into chilli con carne.

Meanwhile, in contrast to the prompt Cabinet reactions to previous rumours of revolts, no senior minister appeared in public to defend Gordon Brown, until the Northern Ireland Secretary, Shaun Woodward, faced the cameras at 2.50pm. Ed Balls and Jack Straw then proclaimed their loyalty.

Other leading Cabinet figures were cautious in their support of the Prime Minister. The Chancellor, Alistair Darling, said the party should be "concentrating on the business of government and getting through the recession". Harriet Harman, Labour's deputy leader, said: "We're all getting on with the job as ministers in the Government which Gordon Brown leads."

But it was the Foreign Secretary, David Miliband, seen by many as Labour's next leader, who was least convincing in his support. "I am working closely with the Prime Minister on foreign policy issues and support the re-election campaign for a Labour government that he is leading," he said, in a statement issued more than six hours after the plotting had begun. He refused to go any further when confronted by journalists last night.

Ministers on the spot: How the plot unfolded

10.24

Labour MPs receive a blank email from Geoff Hoon, the first sign that something is up.

10.58

Geoff Hoon fires off another email, apologising for his earlier blank message.

12.00

As PMQs begins, rumours circulate that Mr Hoon and Patricia Hewitt are preparing a statement on Mr Brown's leadership.

12.26

All Labour MPs now receive an emailed copy of Mr Hoon and Ms Hewitt's letter calling for a secret ballot on Mr Brown's leadership.

12:51

Charles Clarke, the former Home Secretary, becomes the first Labour MP to publicly back the ballot.

13.13

Mr Hoon appears on the lunchtime news and reveals that he had not spoken to any cabinet ministers about holding a secret ballot.

13.14

Ms Hewitt says that the move is "not an attempted coup" and that the ballot could be conducted at next Monday's meeting of MPs.

13.19

Chris Bryant, the Europe minister, becomes the first government member to defend Mr Brown, describing the putsch as "a hand-grenade with the pin still in it".

13.23

The Brown loyalist John McFall says the call for a secret ballot is a "death wish".

14.50

Shaun Woodward, the Northern Ireland Secretary, is the first cabinet minister to go on camera in defence of the Prime Minister.

15.16

Lord Mandelson describes the frenzy over the letter as "a complete overreaction" and says that no one would be resigning.

15:58

Labour's chief whip, Nick Brown, says Mr Hoon and Ms Hewitt have "no significant support".

16.59

A statement from Alistair Darling emerges: "We should be concen-trating on the business of govern-ment and getting through the recession."

17.01

The Home Secretary, Alan Johnson, says that Gordon Brown is, "the best man to lead the Labour Party".

17.10

Ed Miliband appears on TV to say both he and his brother, the Foreign Secretary, David Miliband, back the PM.

17.25

Jack Straw, the Justice Secretary, says he would not be willing to tell Mr Brown to stand down.

18.23

Harriet Harman, Labour's deputy leader, issues her own statement, but the language is cautious. "We're all getting on with the job as ministers in the Government which Gordon Brown leads."

18.33

David Miliband issues lukewarm statement. "I am working closely with the Prime Minister on foreign policy issues and support the re-election campaign for a Labour government that he is leading."

22.40

Lord Mandelson appears on Newsnight declaring the coup a "monumental distraction" that has failed.

The main players

Patricia Hewitt

The former Health Secretary is a Blairite and stepped down from the Cabinet when Mr Brown became Prime Minister. Although she has criticised him over changes to child benefits, she has not been at the forefront of the rebel campaign. After leaving office, she thanked Mr Brown for the offer of a cabinet post and told him he should be "justly proud of [his] achievements". Though perhaps the most surprising of the anti-Brown plotters, she said last summer that the Prime Minister oversaw a "laddish" culture inside No 10.

Geoff Hoon

As a man who was once in charge of overseeing discipline for Gordon Brown, serving as chief whip when Mr Brown moved in to No 10, Geoff Hoon may seem an unlikely political assassin. However, his discontent at Mr Brown's leadership became apparent when he quit as Transport Secretary last June during the previous failed attempt to dethrone the Prime Minister. Sour grapes may also be involved. As a former Europe minister, Blairite Mr Hoon was known to be very keen to take up a role as Britain's EU commissioner last November.

Charles Clarke

Calls from the former Home Secretary for Gordon Brown to go have become a regular feature at Westminster over the past two years as the Norwich South MP has turned himself into the leading critic of the PM's leadership. He quickly backed the call for a secret ballot, but many in Westminster believe he may well have been pulling the strings from the start. The decision for other former ministers to front the campaign may well have been tactical. Even before Mr Brown moved in to No 10, Mr Clarke was briefing against him, suggesting he was a "control freak" who had "psychological" issues.