WASHINGTON (AP) – The Democratic-controlled Senate ignored a veto threat and voted Thursday for a bill requiring President Bush to start withdrawing combat troops from Iraq within four months, dealing a sharp rebuke to a wartime commander in chief.

In a mostly party line 51-47 vote, the Senate signed off on a bill providing $122 billion to pay for the wars in Iraq and Afghanistan. It also orders Mr. Bush to begin withdrawing troops within 120 days of passage while setting a nonbinding goal of ending combat operations by March 31, 2008.

The vote came shortly after Mr. Bush, in a move that his aides said was unprecedented, invited all House Republicans to the White House to appear with him in a sort of pep rally to bolster his position in the continuing war policy fight.

“We stand united in saying loud and clear that when we’ve got a troop in harm’s way, we expect that troop to be fully funded,” Mr. Bush said, surrounded by Republicans on the North Portico, “and we got commanders making tough decisions on the ground, we expect there to be no strings on our commanders.”

“We expect the Congress to be wise about how they spend the people’s money,” he said.