President George Bush's admission, in an interview for ABC, that his "biggest regret" was the "intelligence failure" on Iraq has led to renewed calls for a UK inquiry into the war.
Edward Davey, Liberal Democrat foreign affairs spokesman, has sent a letter to Gordon Brown asking him to include a bill for a public inquiry in tomorrow's Queen's Speech.
Mr Davey said: "With even Bush facing up to the realities of the most devastating foreign policy decision in a generation, how much longer can Gordon Brown stay silent on the part he played in this disaster?
"The case for a public inquiry into the Iraq war is now stronger than ever. Gordon Brown must announce a bill to provide for this in tomorrow's Queen's Speech."
Mr Brown has been firm on the stance that any public inquiry into the Iraq war should not take place until British forces have left the area.
But with the US and Iraqi governments agreeing on a timetabled withdrawal and the British forces in 'overwatch' rather than a combat role, that date could be sooner than first thought.
Anti-war group Stop the War have welcomed the Liberal Democrat's calls for a public inquiry.
A spokesman said: "We have been asking for an inquiry for a long time now and are pleased that the Liberal Democrats have called for this action.
"The Iraq war is both illegal and catastrophic. We can't wait for the forces to leave; it is like having an inquiry into someone being hit in the head and waiting until the other person has stopped hitting them."
This is not the first time that Mr Brown has been under pressure to start a public inquiry into the war; he was advised earlier this year, to hold an inquiry by the Labour-affiliated Fabian Society.
The war costs around £4.3 million a day to fund, and with the country in the throws of a recession politicians are increasingly anxious about its continued political effects
The Home Office has said: "We will not discuss or speculate on the Queen's speech ahead of December 3rd."