Blair said he felt an inquiry was necessary after chief U.S. weapons inspector David Kay testified before the U.S. Senate Armed Services Committee that intelligence about Saddam Hussein's weapons capabilities and his threat could have been faulty.

"We were all wrong and that is most disturbing," Kay told the committee. He resigned from his position as the Iraqi Survey Group's team leader on Jan. 23 after finding no evidence of weapons. The survey group continues to search.

Blair addressed Kay's testimony, saying, "I think it is right, as a result of what David Kay has said, and the fact that the Iraq Survey Group now probably won't report -- in the very near term -- its final report, that we have a look at the intelligence that we received and whether it was accurate or not."

The prime minister's announcement came two days after U.S. President Bush unveiled plans for a similar bipartisan commission to investigate U.S. prewar intelligence.

The intelligence inquiry's mandate
The intelligence inquiry will "examine the effectiveness of structures, systems and processes," according to the official explanation of the inquiry's terms of reference.

The inquiry committee also pointed out that if it believes an individual is laid open to criticism as a result of the inquiry, that person will be allowed to respond before the final report. The committee would consider an individual's need for legal representation in such a situation.

It aims to investigate the accuracy of intelligence on weapons of mass destruction (WMD) in Iraq up to March 2003, and to "examine any discrepancies between the intelligence used by the government before the conflict, and what has been discovered by the Iraq Survey Group since the end of the conflict."

The commission will also look at the intelligence available on WMD programs in other countries considered to pose a threat to the West, and will attempt to assess the state of global trade in these weapons.

The group will then issue recommendations to Blair on the gathering, evaluation and use of WMD intelligence in the future.

The panel will not touch on the politics behind the decision to go to war with Iraq, a controversial omission that has tipped off a furor among critics who say the inquiry's remit is too narrow.

Anger among the opposition
The inquiry was initially supposed to include members from both major opposition parties, the Conservatives and Liberal Democrats. But Blair's announcement of the inquiry's scope caused immediate dissent among the opposition, and the Liberal Democrats immediately announced that they would not participate in the probe.

"The wider issue which most concerns people in this country is the judgments, arrived at by politicians, which were based on that intelligence. They want to know whether we went to war on a false premise. Unless that question is speedily and publicly addressed there is likely to be a continuing erosion of trust in this government," Liberal Democrat leader Charles Kennedy told the Press Association.

Then, on March 1, the Conservative Party also withdrew from the so-called Butler inquiry, citing many of the same reasons as the Liberal Democrats. The Conservatives had previously believed that the inquiry would cover the way intelligence was handled before the Iraq war, and that they would therefore be able to investigate politicians' actions.

In a March 1 letter to Blair, Conservative Party leader Michael Howard wrote that the inquiry, "does not include amongst its aims an examination of the acts or omissions of individuals. It makes clear that it will consider such acts or omissions only in the context of its examination of structures, systems and processes. There is no basis in the terms of reference for that view and I consider it a quite unjustifiable restriction on the committee's approach."

Despite his party's boycott, Conservative MP (Member of Parliament) Michael Mates said he still intends to take the position offered him on the committee.

"I appreciate that Michael Howard has made his decision on behalf of the official opposition, but I believe that my duty is to continue to serve the review as best I can in the important tasks we have been given," Mates said.

Head of the inquiry: Lord Butler of Brockwell
Blair, who selected the committee members, picked former Cabinet Secretary Lord Robin Butler of Brockwell as the group's chairman. Now retired, Butler, 66, has worked directly for three prime ministers; he was private secretary to Edward Heath from 1972-74 and to Harold Wilson from 1974-75.

He was principal private secretary to Conservative Prime Minister Margaret Thatcher, and in that capacity supervised the "secret intelligence feed" that went to the prime minister.

He served as second permanent secretary to the Treasury from 1985-87 and as secretary of the Cabinet and head of home civil service from 1988-98.

He worked to smooth the transition from the Major to Blair governments in 1997, retiring in 1998, less than a year after Blair's Labour Party took power.

The Guardian notes that Butler is "supremely well-qualified to examine whether there were any intelligence failings, or whether ministers put their own gloss on nuanced conclusions from MI6 (Secret Intelligence Service)."

Despite Butler's vast experience, there is also skepticism that he will be sufficiently open with his findings.

In February, the Guardian reacted to Butler's appointment, calling him, "the ultimate Whitehall safe pair of hands," suggesting he is not inclined to cause problems for Blair. The newspaper referred to a former inquiry Butler headed in 1996, which sought to determine whether Britain had allowed arms sales to Iraq.

During that inquiry, he famously noted that "half the picture can be true," words which critics may apply to his viewpoint on the current intelligence inquiry.

Other members of the inquiry committee
Foreign Secretary Jack Straw told members of the House of Commons that four other privy councillors would make up the committee.

The other members are:
-- Right Honourable Sir John Chilcot GCB, a career diplomat with senior positions in the Civil Service on his resume. He served as permanent undersecretary of State in the government's Northern Ireland Office from 1990 until 1997, as well as several positions in the Home Office, Civil Service Department and the Cabinet Office.

-- Right Honourable Ann Taylor MP, a senior Labour Party member and chairwoman of the House of Commons Intelligence and Security Committee, which oversees intelligence services. She was government whip from 1977-79 and government chief whip from 1998-2001.

-- Right Honourable Field Marshal Lord Peter Inge, a member of the House of Lords and former chief of defense staff from 1994-97.

-- Right Honourable Michael Mates MP, a member of the Conservative Party and chairman of the Northern Ireland select committee. Mates has been a member of the Committee on Intelligence and Security since 1994 and was chairman of the Select Committee on Defense Committee from 1987-92.

Timetable for release of the committee's findings
The inquiry conducted private hearings in April and May, with more detailed analysis of written material on certain aspects each part of the investigation. During June and July, the committee was set to re-interview witnesses if deemed necessary and conclude the investigative portion of its work. The committee will then prepare its report, which it will present to Blair before the summer parliamentary recess begins July 22.

Witnesses will undergo questioning from the committee, rather than from legal counsel.

Butler and the other committee members will be granted access to all intelligence reports and assessments and will call witnesses to give evidence in private. Witnesses will include members of the U.K.'s intelligence agencies.

The committee will consult the U.S. Commission on the Intelligence Capabilities of the United States Regarding Weapons of Mass Destruction, under the joint chairmanship of former Sen. Chuck Robb, D-Va., and Judge Lawrence Silberman. The committee's official Web site also says it intends to "keep in touch with the Iraq Survey Group."