WASHINGTON -- Pennsylvania's Rep. John Murtha yesterday predicted that thousands of combat troops would start withdrawing from Iraq as soon as this fall, when President Bush delivers a progress report on the war and Congress considers billions of dollars in emergency military spending.

"When you get to September, this is history. This is when we're going to have a real confrontation with the president," Mr. Murtha, D-Johnstown, told reporters after a meeting of the House Appropriations Committee. "I see signals that things are getting worked out."

In recent weeks, an expanding group of Republican senators has started expressing strong misgivings about the course of the war. Yet only three joined Democrats on July 18 in voting to set a withdrawal timeline, leaving the Senate eight votes short of the 60 needed to end debate on the proposal.

Mr. Murtha, chairman of the House panel on defense spending, said defections among Republicans would grow when Gen. David Petraeus, the U.S. commander in Iraq, gives an update on the president's "surge" strategy, which added 21,500 combat troops there. "If we get an honest appraisal from the field, and they start to accept reality, that will be the directional change," he said.

Mr. Bush on Tuesday didn't seem ready to compromise. "The merger between al-Qaida and its Iraqi affiliate is an alliance of killers, and that is why the finest military in the world is on their trail," he told troops at Charleston Air Force Base, S.C., rebutting critics who say the fighting in Iraq is primarily sectarian.

Some military commanders have said current troop levels will need to remain in place at least until next summer to improve security, according to recent published reports.

"The president has called on Congress to give our troops time to carry out our new strategy in Iraq," said White House spokesman Alex Conant. "The president believes withdrawing before our commanders tell us we are ready would be dangerous for Iraq, for the region and for the United States."

But Mr. Murtha says he has seen a more conciliatory approach from other administration officials, including Defense Secretary Robert M. Gates, who last year replaced Donald Rumsfeld. Bush national security adviser Stephen J. Hadley has made frequent trips to Capitol Hill to meet with congressional leaders.

Next week, Mr. Murtha plans to introduce three amendments to the 2008 defense appropriations bill. One would close the U.S. detention center for terrorism suspects at Guantanamo Bay; another would mandate that all troops heading overseas are "fully trained" and "fully equipped"; and a final amendment would set a 60-day timeline to begin pulling troops from Iraq.

The Pennsylvania lawmaker, one of the leading anti-war voices among congressional Democrats, has pushed unsuccessfully for similar legislation in the past. But he and other party leaders hope to continue placing pressure on Republican lawmakers and the White House.

Yesterday, the House overwhelmingly approved a bill that would prevent the United States from establishing permanent bases in Iraq.

"The Democratic Congress will go on record -- every day if necessary -- to fight for a redeployment of our forces as the central element of a new direction strategy for Iraq," House Speaker Nancy Pelosi, D-Calif., said during the debate.

Mr. Murtha repeatedly emphasized that point with reporters.

"What does redeployment mean exactly?" asked one reporter.

"Get the hell out [of Iraq]," Mr. Murtha replied.

Another asked if any troops would stay behind to engage in counterterrorism operations.

"None, zero," the congressman said. He warned that an evacuation of the U.S. embassy in Baghdad could happen, repeating the images of Americans boarding a helicopter in Saigon during the final days of the Vietnam War in 1975.

He dismissed calls to leave a smaller force of U.S. troops in Iraq, warning that those troops would be more vulnerable to enemy attacks because of the modern military's considerable logistical needs.

Mr. Murtha predicted that a full withdrawal could take as long as a year, as the military tries to remove personnel and heavy equipment.

He argued that a requirement for better training and better equipment for U.S. troops heading overseas would hasten the withdrawal, because the over-extended military can't meet those standards.

"The Army is broken," he said. "The Army is hurting. We couldn't deploy anyplace."

The Bush administration has said all soldiers receive full training before heading overseas, but Mr. Murtha's office said about 60 percent don't have an opportunity to attend instruction centers in the United States that replicate the urban warfare common in Iraq.

Mr. Murtha noted that Mr. Bush and Mr. Gates have expressed a desire to close the U.S. military's Guantanamo Bay prison in Cuba, which holds several hundred detainees and has attracted negative publicity around the world. The congressman said U.S. detention centers could hold terrorism suspects.

His amendments likely won't come up for a vote until September, when Congress returns from its summer recess.