As Labour Party chiefs surveyed the wreckage of the most traumatic 72 hours since Gordon Brown became leader, one man was being singled out for triggering the attempted coup.

The individual in question is a wily political operator with impeccable connections at the highest level of the Labour Party – and a plausible excuse for talking to any plotter.

Little did Nick Robinson, the BBC’s Political Editor, realise when he sat in front of the microphone on Friday morning that his declaration that the threat to the Prime Minister was receding could have the opposite effect.

By the end of the day, Westminster had learnt that eight MPs had written to Ray Collins, Labour’s General Secretary, demanding a vote on Mr Brown’s future at the conference.

Among those who publicly defied the Prime Minister was Siobhain McDonagh, a Blairite assistant whip who was immediately stripped of her job – the start of the latest crisis for Mr Brown. The following day Joan Ryan was sacked from her role as the Prime Minister’s Special Representative for Cyprus. The coup was under way.

Mystery still surrounds how the names of the rebels – who submitted their requests for leadership nomination papers a fortnight ago – became public.

Frank Field blamed Downing Street yesterday, claiming that the rebels’ letters had been leaked by the leadership in a bid to smash their nascent campaign. Mr Brown certainly benefited from the way the news trickled out on a Friday, a day when the media were preoccupied with the collapse of the travel company XL.

But both Downing Street and Geoff Hoon, the Chief Whip, deny that they were involved. Mr Hoon said that he had no idea Ms McDonagh was involved until Friday afternoon.

Most intriguingly, some officials believe that the media were tipped off by one of the plotters, who was furious at the suggestion by Robinson on the Today programme that the threat to Mr Brown had disappeared.

Allies of Mr Brown have suggested that the crisis was less serious than his enemies had hoped. After predictions of a Cabinet putsch, ministerial walk-out or mass collection of signatures, by last night the tally of MPs calling for the Prime Minister to go had reached double figures but was far short of the 71 needed for a challenge.

The massed ranks of the party – many of whom privately despair of Mr Brown – continue to sit on their hands. Alan Milburn and Stephen Byers appear to be biding their time.

Yet any attempt at unity ahead of the Manchester conference was shattered as a string of former ministers took to the airwaves and wrote articles calling for a leadership contest.

Fiona Mactaggart, a former Home Office Minister, told the BBC that someone else should be given a chance to take over. She urged senior ministers to show courage, expressing confidence that there were some who privately supported the rebels.

Barry Gardiner, a special envoy on forestry for the Prime Minister, announced yesterday that he had requested leadership nomination papers be sent out to all Labour MPs.

In The Sunday Times, he said: “The public has stopped listening to Gordon Brown. He is not a popular Prime Minister, but he would continue to have my support if he showed sound judgment, international leadership and political vision. Instead we have vacillation, loss of international credibility, and timorous political manoeuvres that the public cannot understand.”

Another ex-minister, George Howarth, urged Mr Brown to “give somebody else a chance” if he could not recapture the public’s trust. Other MPs who want a challenge to Mr Brown include Graham Stringer, Peter Kilfoyle, John McDonnell and Frank Field.

Cabinet ministers responded by inviting rebels to “have their say” over the leadership in an attempt to flush out plotters before the party conference begins on Saturday. John Hutton, the Business Secretary, admitted that the Government was drifting and called on colleagues to muster the “resolve and resilience” to act.

The Business Secretary angered No 10 by repeatedly refusing to condemn the eight former ministers and MPs who have called for a leadership contest. His failure to slap down the protest could be seen by some as a green light for it to continue. He told the BBC: “I think it is right that there is a debate within the Labour Party, the parliamentary party and the country. Everywhere I go in my own constituency, people are saying, ‘Where are we going? What is happening to Britain?’ We’ve got to be able to answer those questions.”

The focus will now turn to the National Executive Committee tomorrow, where Mr Collins will come under pressure to break with 11 years of convention and send out leadership nomination papers to Labour MPs. “It’s inconceivable that this won’t be discussed in the meeting,” one NEC member said. The move is likely to be backed by some unions, particularly the GMB.

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