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, the ranking member of the Iraqi parliament's defense and security committee, said that negotiations are now over and 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 -- a standard feature of U.S. status-of-forces agreements around the world.

"This is the finish. It is final," said Witwit, a retired Iraqi air force major general. "The major political blocs have reached an agreement, which will not be referred to the parliament, to retain some trainers but without giving them immunity."

A member of the Iraqiya bloc, the junior partner in Prime Minister Nouri al-Maliki's national unity government, Witwit said the decision -- made at a meeting of top Iraqi leaders on Tuesday -- reflects Iraqis' continuing anger that U.S. troops and contractors accused of killing "many Iraqis" have gone largely unpunished by U.S. authorities.

"It stems from the suffering of so many people. So many people were killed, and there was no proper closure," he said.

He added that if U.S. trainers pull out, Baghdad would turn to other countries for training.

Omar al-Mashhadani, a spokesman for the Iraqiya bloc, singled out the systematic mistreatment and torture of Iraqi prisoners at the Abu Ghraib prison in 2003 and 2004 as a reason for Iraq's refusal to grant U.S. trainers immunity. Eleven soldiers were convicted in the case, and a reserve brigadier general was demoted, but no top officer or member of the Bush administration was punished. Al-Mashhadani also mentioned the failure to punish any of the U.S. Marines charged with killing 24 Iraqis in the town of Haditha in 2005.