Milibands at war: A split in the family

Just as MPs are starting to dissent about Ed Miliband's leadership, a new biography suggests his fallout with his brother will be more damaging than the Blair-Brown conflict

David Miliband (left) remains hungry for the job of Labour leader, and is poised, 'waiting for Ed (right) to fail', so he can jump in to save the party (GETTY IMAGES)

The ghosts of New Labour returned to haunt Ed Miliband last week. Tony Blair, with his paperback version of A Journey to sell, turned up to remind the party of what winning looked and sounded like. Then, in scrawled missives on leaked memos, Gordon Brown's hatred of "shallow, muddled" Mr Blair reminded the party how it lost its way because of a generation of feuding between the two.

In one of those memos, Blair told Brown: "The division at the top is killing us." Labour sources described the files as "ancient history". But it is the division at the top of present-day Labour that has the potential to be more destructive than anything the TB-GB wars had to offer: the bitter relationship between David and Ed Miliband.

The first biography of the Labour leader, serialised this weekend, Ed: The Milibands and the Making of a Labour Leader, is expected to reveal how the relationship between the two is worse than ever.

Their mother, Marion Kozak, the book by James Macintyre and Mehdi Hasan is expected to say, is in despair that her close family is falling apart.

It could not come at a worse time for the Labour leader. Last Wednesday, Labour MPs spilled out of the chamber openly complaining of Miliband's "dismal" performance at Prime Minister's Questions, in which he missed the opportunity to score direct hits on David Cameron over the NHS and sentencing.

What was discreet grumbling about Miliband's performance over several months turned into open discussion about his future. One senior shadow cabinet minister has given the leader until the local and mayoral elections next May to improve, or else be challenged.

As we reveal today, David Miliband remains hungry for the job and is poised, "waiting for Ed to fail", so he can jump in to save the party. The memos of Ed Balls leaked to The Daily Telegraph last week have weakened the Shadow Chancellor's reputation. There is a new generation of MPs with no connections to the feuds of the past and present that could offer a strong leader in the future, but for the time being, it is likely that David would win any contest.

As with Blair and Brown, it was the presumption that the older, more experienced man would become leader – only for it to be snatched away by the younger – that is the root cause of the war between the Milibands.

Unlike the Granita "deal" between Blair and Brown in 1994, the Milibands never reached even a loose understanding over the leadership. It was based on assumptions on both sides. In 2009, David Miliband, who at the time was Foreign Secretary, assumed, wrongly, that his younger brother would not challenge him in a race – and Ed Miliband never explicitly told him he would run.

In October 2009, when Blairites still nursed hopes of unseating Brown before the 2010 election, David Miliband was being persuaded by the then Prime Minister to go to Brussels to become the EU foreign affairs minister. David, friends have told The Independent on Sunday, avoided a direct conversation with Ed about his intentions but tried to use the prospect to get his younger brother to back his bid for the leadership, along the lines of "If I stay in Britain, will you support me?".

But Ed "avoided the conversation", said a friend, causing David to "draw appropriate conclusions".

That Christmas, when the two families spent time together, the two brothers avoided the subject altogether. Relations went downhill from there on.

David was, the IoS understands, nevertheless "very, very annoyed" when, after the May 2010 election, Ed announced he would be running for leader – not because it was a surprise, but because Ed had never explicitly told him. In the normal run of politics, this was tantamount to betrayal. But in a close family, with the brothers from early childhood breathing the air of traditional Labour values of comradeship and solidarity, it was the political equivalent of fratricide.

In Balls, who had alienated half the parliamentary party with his Brownite tribalism, David knew he had an opponent he could beat. But his brother was a greater threat: less Brownite than Balls but not tainted by Blair's legacy on Iraq, he was much more appealing to the unions and Labour grassroots.

In June last year, Ed Miliband, in an interview with the IoS, claimed he and his brother would spend Christmas together and "look back and laugh at what a strange thing it was" that they had fought a leadership contest together.

"Whatever happens, I don't think it will affect our relationship," he said at the time. The reality could not have been further from the truth.

After winning the leadership in September, the brothers hugged on stage, but behind the scenes the atmosphere was toxic: David's wife, Louise Shackelton, wept tears of anger and her fury remains. Trying to make amends, the Labour leader offered his brother a seat in the Shadow Cabinet, a major policy review job and the post of chief of staff. All were turned down.

The bitterness, at the moment, is more potent on David's side. Friends of Ed speak of how relations are improving. One aide says they are "brothers first, politicians second". But it is a different story for those around David.

When Ed married his long-term partner, Justine Thornton, last month, there were raised eyebrows that he did not have a best man. Of course, in any normal circumstances, David would have been his best man, but this was now impossible. David and Ms Shackelton attended the wedding in Nottinghamshire but it was "no accident" that they did not go on to the party held by the newly-weds in north London that evening. David claimed he had to attend the Hay Festival instead. But, crucially, his speaking engagement was the following night.

Yesterday, the victory speech that David Miliband would have given to the Labour conference last year was leaked to The Guardian. It contained details of tackling the deficit to restore trust in Labour on the economy. There was talk of immediate action, in contrast to Ed Miliband's "blank sheet of paper". One Labour figure, who wouldn't normally describe himself as a fan of David, said reading the speech felt like being "punched in the gut" at what might have been.

The leaking of the speech was highly provocative. While it is very unlikely that David would openly challenge his brother, the leak is a sign that those around him are mobilising for the succession if Ed can no longer continue.

The friend said: "David definitely wants it still. David is waiting for Ed to fail. He thinks the coalition will go the full term, so he has plenty of time to fail."

Last week, after escaping Westminster with a five-day honeymoon to Seville, Ed Miliband returned to find a deeply depressed parliamentary party. A poll that week had shown Labour only level-pegging with the Tories, after weeks where the party had been ahead. At a meeting of frontbenchers in Portcullis House last Tuesday, he heard the concerns of MPs and his rallying call was, temporarily, successful.

But the next day came PMQs. The Prime Minister told his opponent he was "not really in command of the ship", and afterwards Labour MPs sank into their seats in Westminster's tea rooms, agreeing with the Tory leader.

"Cameron is looking increasingly impressive," said one. Another described Ed as "weak and indecisive". There is a series of policy reviews, but MPs complain that there is no overarching strategy. One complaint is inconsistency – the leader refusing to share a platform with Nick Clegg during the campaign for the Alternative Vote one minute, appealing to Lib Dem voters the next.

Some around the shadow cabinet table who supported David are "trying to make it work", but others are deeply unhappy. An ally of Balls claimed "no one is talking about timescale" but admitted the mood in the party was "dismal".

Tomorrow, Ed Miliband will make a speech calling for a "new era of responsibility" across all levels of British society. There are shades of the speech that are Blairite – perhaps in an attempt to appeal to his brother. But it is difficult to see how the Labour leader can make amends. Ed Miliband has said he would advise his two sons not to go into politics. It is easy to see why.