The Milibands: Man of steel, man of clay

David Miliband's backers blame Harman, the unions, Mandelson – anyone but their man. Brian Brady and Matt Chorley chart how it all went wrong

It wasn't until he opened his front door to the waiting press pack on Wednesday afternoon that the world knew for certain that David Miliband's front-line political career was over.

But, in truth, the man himself had known for the best part of a week. The previous Friday evening, his campaign manager, Jim Murphy, had been on the M6, heading from Scotland for the Labour leadership announcement in Manchester, when he heard some news that brought him to a standstill.

The announcement that Ken Livingstone had been selected as Labour candidate for the London mayoral election should not have been of great interest to the Mili-D campaign – or anyone else beyond the bean-counters and trend-trackers in the deep backrooms of the campaign teams. But the news that the union turnout was below 10 per cent was a bombshell; if the low turnout was repeated in the leadership election, the elder Miliband was in trouble.

"We always thought that a turnout of around 12 per cent would have clinched it for us, because that would have meant more moderate voters in the mix," a senior member of David Miliband's campaign team said. "At 14 per cent it would have been a walk in the park."

Murphy pulled on to the hard shoulder and called David who, apparently, took the news quietly. Barely 24 hours later, he was forced to grin and bear it as, after trailing him for the first three rounds, his younger brother took the prize he had been groomed for. The strong man was beginning a final, fatal falter.

A family drama, a political soap opera played out less than a mile from the Coronation Street set. The choreographed announcement produced an uncommonly exciting start to a Labour Party conference, but the order ended there.

The announcement and, in particular, the unusual familial circumstances dominated events in Manchester last week. It could have been a coronation for a new leader who had been afforded the luxury of several weeks to find his feet following a shorter election campaign earlier in the summer. Instead, those Labour members who bothered to turn up in Manchester witnessed an uncomfortable affair, as a new leader struggled to imprint himself on a backdrop and an agenda designed by someone else for no one in particular. And into the vacuum rushed the farewell speeches, the gossip about the shadow cabinet candidates and the particular family trouble afflicting the Milibands.

As the blame game continues, Labour's deputy leader, Harriet Harman, is never far from the top of Team Dave's list of culprits.

In the days after the general election defeat, and in a major departure from Gordon Brown's dominating style, the party's acting leader consulted the Shadow Cabinet on the timing of the leadership election – particularly the idea of delaying the result until the eve of the September conference. Beginning with Alan Johnson, the shadow home secretary, each member of the Shadow Cabinet said it was a "crazy idea" or "just mad". But, after Ms Harman took the conclusions to Labour's ruling National Executive Committee, they were rejected.

Ed Miliband's campaign team say they always favoured a longer contest, needing time to erode David's position as the front-runner. Publicly, Ms Harman did not back any candidate. But her closeness to Ed Miliband, who worked for her in the 1990s, adds to the theory that she had plotted the timetable for his benefit. That her husband, Jack Dromey MP, was credited with wooing the unions to Ed's cause adds to the impression that the Harman household favoured one candidate, of whom she joked on the last day of the conference: "I can tell you he was always punctual, always neatly dressed, and makes a lovely cup of tea." Certainly, few could imagine Ms Harman giving such an affectionate speech about David.

Private tension between Harman and David Miliband became all too public when the cameras caught him asking her why she was applauding the new leader's condemnation of the Iraq war as "wrong". It was seen as a not-very-heavily-coded "up yours" from the younger brother.

The carping from the David Miliband camp was a regular refrain; in the face of a shocking and shattering defeat, the response of many of them was to lash out against those deemed responsible. If it wasn't Harriet Harman, it was the capricious MPs who drifted away from the elder Miliband (one last-minute switcher was described as "a snake in the grass"). If it wasn't those backbench MPs, it was one of the most important grandees in the Blairite firmament.

The uneasy truce between siblings who had striven not to attack each other during the campaign was shattered twice by Peter Mandelson. First, during an interview with The Times while in Edinburgh, he warned that the more left-leaning Miliband would lead the party into "an electoral cul-de-sac" if he attempted to create "a pre-New Labour future"; later he criticised Ed's role in the compilation of Labour's general election manifesto. "I'm absolutely mystified by the manifesto on which we fought," Mandelson said, "because its creator and author, Ed Miliband, has distanced himself from it, criticised it sharply and created the impression it's not the manifesto on which he would have fought the election."

Mandelson's intervention revived huge divisions within the Labour Party. Ed's campaign manager, Sadiq Khan, immediately claimed the "New Labour attack machine" had been unleashed against the younger brother. "It gave the impression that [Mandelson] was running the campaign," one Mili-D senior explained. It was David who suffered most.

Teresa Pearce, the sort of new MP that the former foreign secretary would have hoped to have signed up, ultimately went for Ed Balls. However, when it came to her next preferences, she was undecided between the brothers; Mandelson made her mind up.

"I supported Ed Balls but it seemed unlikely he would have enough support to win, so I realised my second preference would be important," the Erith and Thamesmead MP said. "I found it difficult to decide between the Milibands but eventually went for Ed after the intervention of Lord Mandelson in criticising the manifesto and Ed's role in its drafting." When Balls was eliminated after the third round, Pearce's vote transferred to her second preference, Ed Miliband, helping him to achieve his narrow victory.

David's supporters claim Mandelson's Edinburgh intervention alone prompted five Labour MPs to switch to Ed. Peeling just six more MPs from Ed would have given David an extra 0.762 per cent in the final round – a tiny amount, but enough to have secured him victory.

Asked what he would change about the campaign, one Mili-D backer wistfully said he would have kept Mandelson away from Edinburgh that Bank Holiday weekend and consigned him to the bottom of a river, "in concrete boots". In a clear signal that the candidate shared his anger over the peer's behaviour, he added: "If David had won and Mandelson had phoned to congratulate him, he wouldn't have taken the call."

David Miliband's team also complained about their lack of access to union membership lists – for campaigning purposes – which they claim were provided to his brother. When David's backers went to town halls to gather the names of local authority shop stewards, they were told data protection laws prevented them being released. A senior Mili-D campaigner later received, via his own union, literature urging him to vote for Ed.

It was clearly an excruciating campaign for David Miliband, but a series of critics have now urged him to look to his own team to explain why he has been confined to a life of back benches and casual shirts.

"Loads of Labour MPs were never going to vote for David first," one veteran explained. "But the trick was to get him ahead of Ed in the preferences, even if it was fourth instead of fifth. But they assumed too much – they didn't try hard enough to pick up the newer MPs who they thought would support him, and when they realised they were getting away, they were too heavy-handed with them."

His brother's team took a more direct approach, partly through their insistence on running an "insurgent campaign" – a description which troubled one of their older members ("I told them I didn't want to be involved in any campaign that didn't set out to win the contest"). David's campaign pulled in more than £200,000 in individual donations, relied on an army of helpers and a "top down" Facebook campaign designed to attract nurses and teachers to his cause. It was not enough; Ed's people claim they were using the site to get to the same people.

The results of the divergent campaign strategies were all too evident on Saturday evening. His closest allies admit Ed Miliband is "not the finished article", but he has demonstrated his potential – and, above all, his steely resolve – over the past three months. It has been a chastening experience for the man who has out-performed him throughout their lives.

On Saturday night after the result, David hosted a meal in a Manchester curry house where he told his team: "No one has anything to be ashamed of." The team now talks of the great lessons they have learned from the experience – unfortunately, they will not get the chance to put them into practice.

The victory, if not the campaign, had been meticulously planned; less so the defeat. David's team have not so far been able to delete his planned leader's speech from their BlackBerrys; the older brother had already allocated jobs in his first Shadow Cabinet. But why, therefore, the agonising hiatus before he announced his future plans?

David's wife Louise Shackelton was "key to the decision" to quit frontline politics, someone close to the late-night discussion over his future admitted. Ms Shackelton, an American-born violinist with no political background – and little interest in the machinations of the Labour Party – is regarded as a "grounding influence" by the couple's friends. She is believed to have been cool on previous potential leadership bids, although she supported her husband this time. Ms Shackelton was visibly upset at the result, and subsequently urged her husband to step back.

The Milibands themselves went through a difficult period at the start of the campaign but were described as "acting like brothers again" at the TUC last month. Their relationship is now described as "strained" by one friend of both. "They need a break from each other," he added, "but they'll come round again."

But, ultimately, after witnessing the friction between Tony Blair and Gordon Brown for so long, David Miliband decided he should go. As one friend said: "If he walks, he looks like a bad loser; if he stays, he becomes a perpetual plotter. How would it work at shadow cabinet meetings? Every time he spoke up people would say he was taking over but if he sat quietly, he would be 'brooding'."

In his longing for a position he saw as naturally his, in his failure to move for it and, when he did, to reach out to his rivals, in his brooding and disruptiveness over just four days, he has appeared more the heir to Gordon Brown than to Tony Blair.

Leadership buzz words: Red Ed's geek tragedy... or is it a psychodrama?

The election of a new Labour leader has been a case study in use of English for Media Studies GCSE courses all over the country.

Top cliché is, of course, "Red Ed", with 145,000 Google hits in the past week. It has been translated into many languages – Ed le Rouge, Der Rote Ed, Ed El Rojo and even Crveni Ed in Serbian. But it has been a good week too for the "family feud", with 26,600 Miliband-related references.

The elder Miliband's decision to step down from the shadow cabinet, to spend less time with one member of his family, has also prompted "sibling rivalry" 21,300 times, "brotherly love" 17,000 times and "brother's shadow" 16,900 times. Surprisingly little interest in "Cain and Abel", a mere 379 mentions, "fratricide", 271, and "geek tragedy", 206 times.

The "geek tragedy" phrase was first applied to the Milibands on Monday last week by Phil Collins, Tony Blair's speechwriter, who is now a leader-writer on The Times. The whole thing has been a "psychodrama", 16,100 times, although it has perhaps been a theatrical production that tells us as much about the psyche of the press as that of the brothers themselves.

Research: Joe Rowley