London - The British government is to hold an independent comprehensive inquiry into the planning and conduct of the Iraq war once the bulk of combat troops have come home by the end of July, Foreign Secretary David Miliband announced Wednesday.

A full inquiry would be set up "as soon as practical" after July 31 when British troop levels will have been reduced to 400 from the current 4,100 troops still stationed in southern Iraq.

"The accumulation of internal lessons learned over the last six years, as well as internal reviews, is all material that an inquiry could draw on," Miliband told parliament.

The Labour government had previously rejected opposition calls for an independent inquiry while troops remained in Iraq. However, Miliband did not give any details of its remit Wednesday.

The inquiry is due to cover the period in the run-up to the 2003 invasion and the process of political decision-making by the previous government of Tony Blair.

It is expected to examine the vexed questions of the legal foundations for going to war and the - now discredited - allegation that Saddam Hussein held an arsenal of weapons of mass destruction.

"The purpose of the inquiry is to learn lessons ... it should indeed be the sort of comprehensive look at the planning and the conduct of the war as well as the conduct of the peace-building afterwards," said Miliband.

Commentators said the inquiry was likely to provide Prime Minister Gordon Brown with a welcome opportunity to "draw a line of distinction" over the Iraq issue between his government and that led by his predecessor.

It is likely to be established in the autumn after the parliamentary summer recess. (dpa)