Two Labour leadership candidates today criticised Britain's decision to join the invasion of Iraq.
Ed Balls became the first former cabinet minister to unequivocally come out and say the Iraq War was "wrong", while Ed Miliband admitted it led to "a catastrophic loss of trust in Labour".
In an interview with The Daily Telegraph, former children's secretary Mr Balls said the decision to go to war in 2003 was an "error" for which Britain paid a heavy price.
"It was a mistake. On the information we had, we shouldn't have prosecuted the war. We shouldn't have changed our argument from international law to regime change in a non-transparent way," he said.
"It was an error for which we as a country paid a heavy price, and for which many people paid with their lives. Saddam Hussein was a horrible man, and I am pleased he is no longer running Iraq. But the war was wrong."
Mr Miliband said UN weapons inspectors were not given enough time before coalition troops invaded.
Speaking to The Guardian, the former energy and climate change secretary said: "As we all know, the basis for going to war was on the basis of Saddam's threat in terms of weapons of mass destruction and therefore that is why I felt the weapons inspectors should have been given more time to find out whether he had those weapons, and Hans Blix - the head of the UN weapons inspectorate - was saying that he wanted to be given more time. The basis for going to war was the threat that he posed.
"The combination of not giving the weapons inspectors more time, and then the weapons not being found, I think for a lot of people it led to a catastrophic loss of trust for us, and we do need to draw a line under it."
Mr Balls, who was an adviser to Gordon Brown in the Treasury at the time of the invasion, said he had warned his boss it was a mistake to try to blame the French for the break down of international negotiations to find a peaceful resolution.
"I was in the room when a decision was taken that we would say it was that dastardly Frenchman, Jacques Chirac, who had scuppered it," he said.
"It wasn't really true, you know. I said to Gordon: 'I know why you're doing this, but you'll regret it.' France is a very important relationship for us."
His comments will be seen as an attempt to distance himself from one of the most controversial legacies of the former Labour government.
Mr Miliband was not yet an MP at the time of the invasion. "I was pretty clear at the time that I thought there needs to be more due process here," he told The Guardian.
His brother and fellow leadership contender, David Miliband, and Andy Burnham, also a candidate, both voted for the war.
The other Labour leadership hopefuls Diane Abbott and John McDonnell were opposed to the invasion.
Despite his reputation as Mr Brown's closest lieutenant, Mr Balls insisted they often argued. He said: "I had more blazing rows with him than anyone. You had to do that sometimes to shut Gordon up."
Mr Balls also confirmed that he had offered to stand aside to allow his wife, former work and pensions secretary Yvette Cooper, to run for the leadership, but she had declined.
"We've talked about it for years. We didn't have a summit or choose a restaurant. I offered to stand aside, but she thought it wasn't the right time for her. She didn't want to do it."
Ed Miliband said he had "some very heated arguments" with Mr Brown about the cabinet decision to go ahead with a third runway at Heathrow airport and had even considered resigning from the government over the issue.