BAGHDAD – The possibility that some U.S. troops would remain in Iraq past the current Dec. 31 withdrawal date appeared all but doomed Wednesday as Iraqi political leaders ruled out any special legal protections for military trainers who stay behind.

U.S. officials, who have been advocating a continued presence past the withdrawal date set in a 2008 agreement, held out hope that some sort of accommodation might still be reached.

But Iskander Witwit, of the Iraqi parliament’s defense and security committee, said that U.S. trainers would be invited to remain only if U.S. officials drop their insistence that the Iraqi parliament grant them immunity from prosecution in Iraq .