LONDON - The government said Tuesday it would veto publication of minutes from ministerial discussions about the legality of the 2003 invasion of Iraq, immediately drawing accusations of a cover-up.
Anti-war campaigners believe the minutes may conceal damaging information about how then prime minister Tony Blair's government reached the decision to support the US-led invasion.
However, current Prime Minister Gordon Brown's administration fears publishing the minutes may hinder ministers' ability to speak freely at confidential weekly Cabinet meetings.
"Confidentiality serves to promote thorough decision-making," Justice Secretary Jack Straw told parliament's lower House of Commons.
"Disclosure of the Cabinet minutes in this case jeopardises that space for thought and debate at precisely the point where it has its greatest utility.
"In short, the damage that disclosure of the minutes in this instance would far outweigh any corresponding public interest in their disclosure."
Some lawmakers greeted his announcement with cries of "shame!"
One who supported his decision was Lord Robin Butler, once Britain's highest ranking civil servant, who said Cabinet minutes should be exempted from the freedom of information rules under which the government had faced calls to release the minutes.
"There will always be an inhibition to candour in important discussions in government because those taking part in them will be uncertain whether what they are going to say is going to be revealed under the Freedom of Information Act or not," said Butler, who led a 2004 inquiry on government intelligence on weapons of mass destruction in the lead up to the invasion.
The government's unprecedented move came after the Information Tribunal watchdog last month ordered the release of minutes from Cabinet meetings on March 13 and 17, 2003, when ministers had discussed whether war was allowed under international law.
Campaigners are particularly keen to get hold of the minutes due to concerns about advice given to Blair's Cabinet by Peter Goldsmith, then the attorney general, or senior legal adviser.
In advice published on March 17 of that year, Goldsmith stated that military action against Iraq was legal. But Goldsmith's earlier, more equivocal counsel was not disclosed at that stage and eventually leaked out.
Goldsmith then denied that ministers had pressured him into changing his mind to rule that invading Iraq would be legal under international law, even without a second United Nations Security Council resolution.
Blair faced heavy criticism from many for backing former US president George W. Bush in invading Iraq to oust dictator Saddam Hussein despite failing to secure a second UN resolution.
Kate Hudson, chairman of the Campaign for Nuclear Disarmament, called the veto "disgraceful," adding it was "yet another attempt to suppress public debate on the biggest political scandal in decades."
"The use of the veto cannot be justified in any way -- there is no risk to candid discussions in Cabinet as such minutes do not single out those making each point," she said.
"The disgrace of the attorney general 'changing his mind' on whether the war could be justified must be exposed in all its detail."
Straw's move was backed by the main opposition Conservative Party, although justice spokesman Dominic Grieve urged a public inquiry into Britain's involvement in the Iraq war.