Leading Blairites last November sounded out Alan Johnson, the former home secretary, on whether he intended to stand against Ed Miliband as Labour leader, amid simmering unrest in the party.
Peter Mandelson, former trade secretary, was asked by a number of Labour MPs — including those who would have supported a leadership challenge — to see whether the centrist Mr Johnson planned a move.
Meanwhile Alastair Campbell, Tony Blair’s former press secretary, also asked Mr Johnson about rumours he intended to stand. Allies say Mr Campbell was “worried about the seeming frenzy developing”.
The Labour grandees confirmed the conversations took place at the height of speculation about a leadership challenge to Mr Miliband, but deny categorically that they wanted — or tried to persuade — Mr Johnson to strike.
Mr Johnson, now a successful author, said he had no interest in taking over as Labour leader. This ended a last push by MPs critical of Mr Miliband to topple him. “Alan gave an emphatic No,” one Labour MP said.
The calls reflected what one senior party described as the “sense of meltdown” at the time. Lord Mandelson said: “I’m a friend of Alan’s. But talking to him at this time is not the same as urging him to stand and I didn’t do so.”
Mr Miliband dismissed talk of a possible coup at the time and Sadiq Khan, shadow justice secretary, said: “I never saw him nervous, shaky, scared. There was just frustration that people were distracted by that nonsense.”
An FT Weekend Magazine interview with Mr Miliband reveals a leader with a remarkable self-belief in spite of the criticism aimed at him. “I think Britain needs a Labour government and it needs a Labour government led by me,” he says.
Asked whether he ever doubted whether the party had chosen the wrong leader — passing over his brother David — he replies: “Definitely not.”
Mr Miliband admits the 2010 leadership contest was “hard” for his older brother, but says: “I see him when he’s over here and we talk. It was tough but it feels a lot easier and better now.”
The conversations involving Mr Johnson took place at a time when Mr Miliband was under attack from some of his own MPs, after a lacklustre Labour conference speech when he forgot to mention the deficit.
The party’s popularity slump in Scotland and an attack on the “Hampstead socialist” by the editor of the formerly loyal New Statesman magazine added to a febrile mood, with one senior party figure saying that the situation was “close to meltdown”.
Blairite criticisms of Mr Miliband have continued into 2015, with former prime minister Tony Blair warning that leftwing parties did not win elections, and Alan Milburn and John Hutton — two Labour former ministers — writing in the Financial Times that the party had ceded the economic battleground to the Tories.
Mr Miliband’s allies say that acts of what he sees as disloyalty to the party — and the pursuit of “personal agendas” — anger him. He made a furious telephone call to Lord Mandelson last month after the peer criticised the party’s “crude” mansion tax.
Relations between the two men are said to have improved, however, while Mr Campbell is now advising Mr Miliband on the proposed television election debates, playing the role of a “brutal” David Cameron.
One shadow minister says Mr Miliband can take the heat: “He’s hard. He can be brutal. He did in his brother — I wouldn’t have done that. If you’re out of line, you’re gone.”
Mr Miliband tells the Financial Times that he expects to be the target of sustained media hostility between now and the election but adds: “If we were miles behind in the opinion polls they wouldn’t be doing it. It’s because they fear I’m going to win.