The decision to join the US in fighting the Iraq war became the focus today of the most bitter exchanges yet between the two Miliband brothers in their rival campaigns for the Labour party leadership.
In a two-hour Radio 5 hustings, David Miliband claimed that his brother Ed was in the same position over the Iraq war as all the other candidates save Diane Abbott, since she alone had vocally opposed the conflict at the time.
Ed Miliband has claimed that he opposed the war at the time of the invasion in 2003 but was living in the US, so his views were not known in the UK.
His claim was repeatedly challenged by leadership contender Ed Balls.
Balls said: "I do not think Ed or any of the rest of us can claim with any credibility that in 2003 we thought the war was wrong but we just forgot to tell anyone, because that would make us look ridiculous."
The pointed exchanges started when Ed Miliband sought to distinguish himself from his brother, saying: "One of the differences between David and myself is I think I am more critical of some of the things we did in government, and more willing to move on from some of the mistakes that we made, not just on foreign policy, like Iraq, but on the economy and the fact that we have left lots of people on low wages.
"Unless you are willing to say we made mistakes and you are willing to move on from them we will have the same result at the next election."
David Miliband countered: "I do not believe we lost the 2010 election because of Iraq and we fool ourselves if we think [we lost] places like Stevenage – that we won in 2005 – because of Iraq."
He added: "We have all said that if we had known in 2003 there were no weapons of mass destruction then of course we would not have voted for the war."
He asserted: "Diane Abbott is the only candidate that can say she was against the war at the time, and if that is the sole criterion, she is in a different position to every other candidate. She did not just think she was against it, she said she was against it, and she marched against it."
Ed Miliband insisted on his opposition: "I did tell people at the time that asked me that I was against the war."
Balls said under his breath "you did not tell people" before pointing out that in 2005, when the Times asked Labour figures whether they would have voted for the war, Ed did not answer the question.
Ed Miliband countered that he did tell his constituency party in 2005 of his opposition, but denied he was seeking any moral superiority.
"We hitched our wagon to the US on foreign policy in a way that was a profound mistake," he said.
His brother countered: "The true profound issue is whether the Labour party wants to choose its leader by looking backwards and inwards, or forward and outward."
Balls said he now apologised for the decision to back the war, while Andy Burnham said: "It was the most agonising process I have been through in my life."
Ed Miliband also came under fire when he said he thought the government had helped fuel anxiety on immigration by being too soft on business in applying the agency workers directive, a law designed to regulate cheap labour.
Abbott angrily intervened: "You were a member of that cabinet. Why was that cabinet so willing to listen to business? It is no good wringing your hands now. Why did you go along with it?"
Balls said he may decide in September whether he is willing to recommend a second preference candidate.
Andy Burnham insisted he was different to his colleagues, saying: "What people are looking for as a leader of the Labour party is someone from an everyday background who speaks everyday language, not the language of thinktanks."
He highlighted a national care service free at the point of use to provide care for the elderly, funded from a 10% tax on estates, stating: "At the moment we have a dementia tax."