Democratic aides expressed growing confidence of success when the vote is called, which could be today. They pointed to support from some longtime opponents of the war.
"I want this war ended today. If I thought it would help this war ending sooner by voting against the bill, I would vote against it in a heartbeat," said Representative James P. McGovern of Massachusetts, who sponsored legislation for a troop withdrawal in 2005.
"But I don't believe that to be the case," he added of the measure, which combines funding for the war, the troop withdrawal deadline, and billions of dollars in funding for politically popular programs at home ranging from farm aid to relief for the victims of Hurricane Katrina.
The legislation marks the most direct challenge by Congress to date of Bush's policy in a war that has claimed the lives of nearly 3,200 US troops.
As debate began in the House, Republicans criticized it vociferously. "The bill is a sham," said Representative Harold Rogers of Kentucky, adding that it would "provide fodder for our enemies abroad."
Bush has threatened to veto the bill, opposing both the troop withdrawal provision and the billions of dollars in spending that Democrats added.
Defense Secretary Robert M. Gates said any delay in approving the funds could "have a genuinely adverse affect on the readiness of the Army and the quality of life for soldiers and their families."
White House press secretary Tony Snow sharpened the message. "There's a very real chance that money for the troops will run out while members of Congress are on vacation," he said. "Is that the message you want to send to men and women who are putting their lives on the line?"
Across the Capitol, a Senate committee launched legislation taking a slightly different approach -- setting a date for the beginning of a withdrawal but only a nonbinding goal of March 31, 2008, for the final exit of combat forces.
The measure cleared the Senate Appropriations Committee on a voice vote, but Republicans said they would attempt to strip out the withdrawal provisions when the issue comes before the full Senate next week.
