Prime Minister Gordon Brown will announce an inquiry into the Iraq conflict in a statement to MPs.
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 on Monday.
The Government has consistently 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.