A British soldier uses the scope on his rifle while on patrol in Basra in 2008. An investigation is underway in Britain into the country's involvement in the Iraq war. (Nabil al-Jurani/Associated Press)

An investigation into Britain's involvement in the Iraq war opened public hearings Tuesday with a moment of silence for those who died in the conflict.

The probe is expected to examine the leadup to the war, and whether former U.K. prime minister Tony Blair pledged support for former U.S. president George Bush's invasion of Iraq even before the U.K. Parliament approved military involvement in 2003.

The investigation's panel, which was appointed by Prime Minister Gordon Brown, won't lay blame, or establish criminal or civil liability. The panel will offer reprimands and make recommendations.

Former British prime minister Tony Blair will testify before a U.K. government inquiry into the Iraq war. (Sang Tan/Associated Press)

"Our determination is to do not merely a thorough job, but one that is frank and will bear public scrutiny," panel chair John Chilcot, a retired public servant, told CBC News.

Some worry the hearings will do little to answer lingering doubts about Britain's rush to join the war.

"I don't think it will satisfy people who are hoping to hang, draw and quarter Tony Blair, or refer him to the International Court — that's not going to happen," said Clare Short, an ex-cabinet minister who quit in protest two months after the invasion. She will also be testifying before the inquiry.

Blair is expected to appear before the panel early next year. Military officials and the heads of spy agencies are also expected to testify.

While witnesses in the investigation won't have to take an oath, Chilcot said he assumes they will, adding that it's the inquiry's job to make sure they do.

One of the first witnesses, Sir William Patey, who was head of the Middle East department at the U.K. Foreign Office in 2001 and is now Britain's ambassador to Saudi Arabia, said that back in early 2001 that there was little appetite in the British government for the ouster of Saddam Hussein.

"Our policy was to stay away from that," he said. "We didn't think Saddam was a good thing, and it would be great if he went, but we didn't have an explicit policy for trying to get rid of him."

Patey said that stance continued even after the Sept. 11 attacks against the United States.

The five-member panel is due to report by the end of 2010, but it may take longer than that if the evidence presented to it proves complex.

A total of 179 British soldiers lost their lives during the U.K. involvement in Iraq.

Some relatives of dead soldiers demanded the chance to question Blair when he gives evidence to the panel — an idea rejected by the inquiry.

"He has got to face us, and tell us why we went to war, and when exactly that decision was made," said Rose Gentle, whose 19-year-old son Gordon was killed in Iraq in 2004. She said many bereaved parents will attend Blair's sessions.

The report won't come in time for the next U.K. general election, which must be held by June 2010.

With files from The Associated Press