David Miliband admitted yesterday that the Government had been wrong to attempt to hold the inquiry into the Iraq war in secret.
The Foreign Secretary also acknowledged that ministers had been forced to drastically change their position by the force of public opinion.
Mr Miliband, the first minister to make the controversial announcement that evidence would heard behind closed doors and then initially left to weather the storm of protest which followed said: "The unanimity of view that actually we need public sessions for this inquiry is something that the Government has listened to."
Asked if Gordon Brown had "got it wrong" when he insisted last week that the inquiry would be behind closed doors, Mr Miliband said: "We obviously did. There is no question about that. No one is arguing that we changed our position."
The Independent revealed that senior military officers such as General Sir Mike Jackson, the head of the Army at the time of the Iraq invasion and Lord Butler and Lord Hutton, who had headed previous inquiries related to the war, wanted the hearings to be in the public. Former prime minister, Sir John Major, was among those who also opposed a secret hearing.
Mr Brown was forced to let Sir John Chilcot decide on the terms of the inquiry and Sir John stated that in his view it was "essential" that as much of the evidence should be heard in public as possible.
A humiliating Commons defeat for the Government on the issue was averted on Wednesday when Mr Miliband withdrew another of the initial Downing Street plans for the inquiry – that it would not apportion blame – and agreed that the final report could "praise or blame whoever it likes".
The retreat helped the Government see off a backbench revolt over the inquiry arrangements, although its majority was still slashed to 39.
A Tory motion demanding a re-think and a Commons vote on the inquiry's terms of reference was backed by 19 Labour MPs.
Earlier, Downing Street denied that Mr Brown had struck a deal with Lord Mandelson to spare Tony Blair from having to give evidence to the inquiry in public as the price of saving his premiership.
There had been claims that Lord Mandelson had won an "explicit" assurance from Mr Brown that the inquiry would be fully private and that it would be "manageable".
However, both Lord Mandelson and Mr Brown were said to have been taken by surprise by the strength of the opposition from senior military and Whitehall figures to a closed inquiry.
The Prime Minister's spokesman dismissed the report as "flawed", insisting that Mr Brown had not entered into any deals. We would certainly deny the suggestion that the Prime Minister has done any sort of deal," the spokesman said. We are not having the inquiry in secret so the whole premise of the article does seem to fall down on that basic point."