London, Nov. 17 The current and former chiefs of the UK's intelligence service, MI6, will be the first witnesses to testify and give evidence in the official inquiry into the Iraq war.

Sir John Scarlett, who retired as director general of the Secret Intelligence Service last month, will be questioned about his chairmanship of the Joint Intelligence Committee (JIC).

His predecessor Sir Peter Ricketts will also be quizzed.

Between 2001 and 2004, he oversaw the Government's dossier on Iraq's alleged weapons of mass destruction.

Sir John Sawers will be called to speak about his time as the private secretary with responsibility for foreign affairs to then Prime Minister Tony Blair.

The Iraq Inquiry to be chaired by Sir John Chilcot will hear testimonies of 20 top advisers, diplomats and military figures.

"We will cover a wide range of topics during these hearings. Those topics will include UK government policy on Iraq between 2001 and 2003, transatlantic relations during this time, policy and intelligence on weapons of mass destruction, and planning by the military and other governmental bodies for the invasion and its immediate aftermath," The Independent quoted Sir Chilcot, as saying.

Others to give evidence include: Sir Christopher Meyer, the British ambassador to Washington until 2003, Sir David Manning, foreign policy adviser to Blair until 2003, Admiral Lord Boyce, the head of the Armed Forces until 2003.

Former Prime Minister Tony Blair is expected to be summoned early in the new year.

The first hearing will take place on November 24, and the inquiry is not expected to report until the end of 2010, or even 2011. (ANI)