Gordon Brown will announce an inquiry into the Iraq war in a statement to MPs this afternoon.

Mr Brown's spokesman said: “The Prime Minister’s statement will be on the end of the UK’s military mission in Iraq and an inquiry into the conflict.”

The spokesman declined to give any more details of the long-awaited inquiry - such as whether it will take any evidence in public or who will chair it - in advance of Mr Brown’s Commons statement, expected at 3.30pm.

The Government has previously said an inquiry will be held after the UK’s combat role in Iraq has ended.

British troops conducted their last combat mission on April 30 and their withdrawal is expected to be completed by July 31.

The inquiry is expected to follow the model of the Franks Inquiry into the 1982 Falklands War, which met in private.

Lindsey German, convener of the Stop The War Coalition, said nothing short of a full public inquiry, leading to possible prosecutions, will satisfy the millions who marched against the war and the families of soldiers killed in the conflict.

She said: “There needs to be a full public inquiry to find out exactly why we were taken to war and to investigate the discussions between Tony Blair and George Bush in 2002.

“We need to know the thinking behind the dossier - and the lies - of weapons of mass destruction as well as the involvement of ministers, including Gordon Brown, who financed the war as Chancellor.”

Opponents of the war are expected to stage a demonstration at Parliament as Mr Brown makes his announcement.

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