Updated

Some congressional Democrats are insisting that the White House provide more information about what led to the decision to go to war in Iraq, citing a British document known as the "Downing Street memo (search)" as evidence intelligence was distorted.

Rep. John Conyers (search) and other Democrats on the House Judiciary Committee conducted a public forum Thursday prompted by documents that have surfaced from inside the British government about prewar planning.

Former Ambassador Joseph Wilson (search), who advised the Bush administration in 2002 that Saddam Hussein had not tried to buy a certain kind of uranium from Africa, said Conyers' hearing was important.

"We are having this discussion today because we failed to have it three years ago when we went to war," Wilson said.

"It used to be said that democracies were difficult to mobilize for war precisely because of the debate required," and the lack of debate in this case allowed the war to happen, he said.

Wilson wrote a 2003 newspaper opinion piece criticizing the Bush administration's claim that Iraq had sought uranium in Niger. After the piece appeared someone in the Bush administration leaked the identity of Wilson's wife as a CIA operative, exposing her cover.

Wilson has said he believes the leak was retaliation for his critical comments. The Justice Department is investigating and two reporters are being threatened with jail time for refusing to divulge their sources on the issue.

The Downing Street memo says the Bush administration believed that war was inevitable and was determined to use intelligence about weapons of mass destruction to justify the ouster of Saddam.

The "intelligence and facts were being fixed around the policy," says the memo, recounting a July 23, 2002, meeting of Prime Minister Tony Blair and his national security team. The meeting took place just after British officials returned from Washington.

U.S. officials and Blair deny the assertion about intelligence and facts being "fixed," a comment that the memo attributes to the chief of British intelligence at the time. The meeting took place eight months before the invasion of Iraq.

Conyers pointed to statements by Bush in the run-up to invasion that war would be a last resort. "The veracity of those statements has — to put it mildly — come into question," he said.

The London Sunday Times disclosed the contents of the memo May 1.

Bush should respond to questions raised by the Downing Street memo, says a letter signed by Conyers and over 90 other members of Congress, as well as a half-million Americans.

White House press secretary Scott McClellan dismissed the memo on Thursday and indicated that no one in the White House plans to respond to the letter.

"This is simply rehashing old debates that have already been discussed," he said.

The Sunday Times also reported on an eight-page briefing paper prepared for Blair which concluded that the U.S. military had given "little thought" to the aftermath of a war in Iraq.

The briefing paper of July 21, 2002, said a postwar occupation of Iraq could lead to a protracted and costly nation-building exercise and that "as already made clear, the U.S. military plans are virtually silent on this point. Washington could look to us to share a disproportionate share of the burden."