When you are plotting to sack your leader, it is important that you are seen to be doing your duty. The proper thing for Labour MPs yesterday was to be out on the doorsteps, trying to persuade voters to head for the polling booths.
As MPs fanned out around the country, Westminster's corridors and bars – where plots are traditionally hatched and abandoned – were deserted. And what had previously been a conspiracy by email turned into a conspiracy by mobile phone.
In between conversations with hostile voters, the plotters had their ears clamped to handsets, encouraging wavering backbenchers to rebel.
In most places, the electors' reaction was utterly discouraging for Labour, as people who have turned out for the party in election after election refused to make eye contact and became strangely evasive about their voting intentions.
As the voters blew cold, the conspiracy heated up. "I have found people shifting their view about Gordon," one of the conspirators told The Independent yesterday, after a series of telephone conversations with fellow MPs about what they were hearing from the voters. "They are saying we are not going to survive unless there's movement at the top of the party."
He added: "There's a huge level of dissatisfaction not just in the PLP [Parliamentary Labour Party], but in the wider party as well. There are over 100 MPs dissatisfied with our direction. Whether they are willing to put their heads over the parapet is another matter."
One former minister who wants to see Gordon Brown replaced by Alan Johnson said: "It's just awful to campaign for Brown when you have got no belief in him.
"People are coming up and saying we should have got rid of him last year. But Brown doesn't care about the party – he only cares about himself. He is delusional if he doesn't realise what's going on."
Another ex-minister said: "I don't think that Gordon can survive now, and I have signed the letter calling for his resignation. I think there will be a sufficient number of names to force him to step down."
He said he had been approached for his signature by the former home secretary Charles Clarke, but added that Mr Clarke is not acting alone: "There are lots of people collecting names."
The plan is still to present the Prime Minister with a letter bearing the signatures of at least 50 Labour MPs, calling on him to resign. The malcontents want to hand it over as early as today, but could hold back until Sunday, after Mr Brown has returned from the D-Day anniversary celebration in Normandy.
No one expects the letter, on its own, to drive Mr Brown out of office, but the conspirators hope it will act as a catalyst that will induce the Cabinet – notably Jack Straw or Alan Johnson – to tell him that he has to go.
One conspirator, speaking with the sound of an election loudspeaker in the background, said: "While the peasants will continue their revolt with their pitchforks, the real people who need to step up to the plate are Cabinet ministers. We need people with courage and conviction to come forward.
"There are a huge number of people in the Parliamentary Labour Party who want to ensure the leadership issue is dealt with speedily and respectfully."
Gordon Brown's allies have already given the rebels notice that, no matter how bad the results of yesterday's vote prove to be, the Prime Minister intends to stay on. In an attempt to get their retaliation in early, the Chief Whip, Nick Brown, gave out the names of MPs he believed were implicated in the plot.
One of the names they gave out was Paul Farrelly, MP for Newcastle-under-Lyme, who said yesterday that he had neither signed, nor even seen, any letter calling on Mr Brown to resign. He suspected that the reason he was named was that Mr Brown, who has been personally ringing backbench Labour MPs asking for support, had called him twice, but he had not returned the call because was busy with a last-ditch effort to try to save Labour from losing control of Staffordshire Council.
Furious, he said: "This is yet again bad behaviour by the clique around Gordon Brown. They never learn, and it's totally unacceptable. They should really reflect on whether they are fit, morally and in practice, to lead the Labour Party. They have learnt nothing from the Damian McBride fiasco in shoving names out indiscriminately just because some people may be privately critical of the Government or of government policy.
"It's a bunker and siege mentality that will lead the Labour Party off a very steep cliff, and things have to change quickly."
Two others named by Downing Street, the former Cabinet ministers Alan Milburn and Stephen Byers, were also not involved in the plotting, since both were on separate business trips in the Middle East yesterday. Mr Clarke, who is one of the instigators, was not on Downing Street's list of suspects.
John McDonnell, a left-wing Labour MP, also complained yesterday about "dirty tricks" orchestrated in Downing Street. In a letter to the Prime Minister, Mr McDonnell said: "I am writing to ask you to ensure that your office desists from this briefing activity. It is not my style to undertake this type of covert attack on a colleague."
And the powerbrokers who will determine if they succeed
The Justice Secretary is the most senior of the "men in grey suits" who could tell Gordon Brown to quit for the good of the party. Friends say he has no intention of doing that. But the oldest Cabinet member is famous for sensing which way the political wind is blowing. Were he to tell Brown his time was up, the PM would find it impossible to ignore him.
It is said that in politics the assassin never inherits the crown, so as the man most likely to succeed Gordon Brown the Health Secretary will keep well away from any move to force him out. "He is doing the job and there is absolutely no one who could do [it] better," Johnson said, even as plotters were collecting signatures calling on Brown to quit.
The Chancellor has been a good friend and ally of Brown for many years but it is said that he will refuse to be moved to another Cabinet post, forcing Brown to keep him where he is or sack him. Brown has to assert his authority over his Cabinet if he is to survive. His old friend could be the obstacle that makes the reshuffle go horribly wrong from the start.
Although the Dagenham MP has never been a minister, he has a strong following in all sections of the party. Were he to stand as a stalking horse candidate – a plan his allies deny – he could win support from dozens of backbenchers with his bid to reconnect with grassroots voters. Given the turbulence in Labour ranks, he could even win the top job.
The surprise winner of the Labour deputy leadership contest is among the party's most powerful figures.
Her close links to Gordon Brown make it almost certain she would not deliver the "black spot", but she would be well placed to relay to him the despair among backbenchers. Could that message persuade Brown to quit?