London, Nov. 27 : British and American officials were desperately looking for a "smoking gun" that would justify their imminent invasion of Iraq, an official inquiry has heard.

Sky News quoted Sir Christopher Meyer, the former British ambassador to the US, as saying the Bush administration''s stringent timetable for military action was too tight and did not allow enough time for UN inspectors to properly carry out their searches for Saddam Hussein''s elusive weapons of mass destruction.

The official inquiry is examining the relationship between former British Prime Minister Tony Blair and President George W. Bush.

The two leaders may have agreed Saddam should be overthrown in private discussions at the US President''s Texas ranch in April 2002 - 11 months before the war, Sir Christopher said.

"By the time the President and the Prime Minister met at Crawford (Mr Bush''s ranch) they weren''t there to talk about containment or sharpening sanctions," Sir Christopher added.

He said the change in stance was illustrated in a speech given by the Prime Minister a day after the talks.

Sir Christopher went on: "To the best of my knowledge, I might be wrong, this was the first time that Tony Blair had said in public ''regime change''.

Sir Christopher, the UK''s representative in Washington DC between 1997 and 2003, described how US policy changed when Bush became leader in 2001 and focused more on "regime change" in Iraq.

Commission chairman Sir John Chilcot has already warned that today''s session would be detailed and laborious.

The former ambassador is the latest senior figure to appear at the public hearings which are being chaired by Chilcot. (ANI)