During nearly three hours of testimony, the then international development secretary, who resigned soon after the March 2003 invasion as a result of what she called broken promises, described the atmosphere within the government during the run-up to war. It was chaotic and fraught, she said, adding: "We were in a bit of a lunatic asylum."

Short described how she used to meet Gordon Brown in the weeks before the invasion. "I had various cups of coffee with Gordon," she said. "He was very unhappy and marginalized."

She said Brown, then chancellor, told her: "Tony Blair is obsessed with his legacy and he thinks he can have a quick war and then a reshuffle."

But as war was getting closer, "Gordon was back in with Tony," she said. She said the two men together blamed the French for the failure to get a new United Nations resolution.

"In my view that was a lie, a deliberate lie," she said, referring to claims that President Jacques Chirac said France would veto a fresh U.N. resolution in any circumstances. "Blame the French, concoct the legal authority and off we go," she said. "The British government's capacity to think better than that is thrown away, to our eternal shame."