IRAQ has failed to meet all but three of 18 benchmarks for political and military progress, says a leaked report being prepared for the US Congress.

The draft is strikingly negative, and raises questions about statements by the President, George Bush, last month, when he offered a much more positive assessment.

The Government Accountability Office report is to be presented to Congress on Tuesday.

A separate report due late next month based on the White House's own new benchmarks and congressional testimony from General David Petraeus, the commander in Iraq, and the US ambassador, Ryan Crocker, is expected to be more positive.

The conflicting views of the war in Washington came as Moqtada al-Sadr, the influential Iraqi Shiite preacher, ordered his Mahdi Army gunmen to halt all hostilities for six months, including attacks on coalition troops.