U.S. soldiers of the 1st Platoon, Alpha Company, 2nd Battalion, 12th Cavalry Regiment take position as they patrol a street in Baghdad's north-west Shi'ite neighborhood of Sholla March 20, 2007.[Reuters]

WASHINGTON - US Senate Democrats on Wednesday revived legislation urging President Bush to bring combat troops home from Iraq in a year, attaching the plan to a $122 billion measure needed to fund the war.

The move puts Democrats on track for another confrontation with Bush over the increasingly unpopular war and with Republicans, who are expected to try to block the measure.

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House Democratic leaders are pushing a similar measure that would require that troops leave by the fall of 2008. Party officials predicted the House would pass it on Thursday, albeit by a razor-thin margin.

"United States troops should not be policing a civil war, and the current conflict in Iraq requires principally a political solution," says a draft Senate bill circulated to lawmakers in anticipation of a committee vote Thursday.

The measure would provide nearly $97 billion for the wars in Iraq and Afghanistan and billions more in domestic aid and emergency relief programs. It would require that Bush begin bringing home some troops within four months of the bill's passage, setting a nonbinding goal of having all U.S. combat troops out of Iraq by March 31, 2008.

The provision is similar to a resolution the Senate rejected last week. The vote then was 50-48, 12 shy of the 60 needed to pass, after Bush pledged to veto the legislation.

Democrats think the spending legislation has a much better chance. Sen. Ben Nelson, D-Neb., who voted against last week's proposal, has agreed to support the spending bill because it outlines benchmarks for the Iraqi government.

Democrats also think Republicans will be reluctant to reject a much needed spending bill that would fund popular projects in their states in favor of the war.

Senate Majority Leader Harry Reid, D-Nev., "continues to believe that despite the high-fives the Republicans had last week, there's serious heartburn in the caucus over the war," said his spokesman, Jim Manley.

So far, Republican leaders say they will reject the bill.

"We must not risk providing our troops the equipment and supplies they need to carry out their mission by including this risky Democratic leadership retreat plan, this poison pill," said Senate Republican leader Mitch McConnell of Kentucky. "We owe our troops better than that."

Sean Kevelighan, spokesman for the White House budget office, said it is "unfortunate that the Senate is wanting to delay vital funds for our troops by producing a bill that mirrors House legislation that will never become law, attempts to tie the hands of our military commanders and is a Christmas wish list of nonwar related spending add-ons."

The House was expected to vote Thursday on a similar $124 billion spending bill that would finance the wars. The bill, which Bush also threatened to veto, would require that combat troops be out of Iraq before September 2008, possibly sooner if the Iraqi government does not meet certain benchmarks.

House Speaker Nancy Pelosi, D-Calif., pressed Democrats to back the bill, unsure whether she had enough votes to pass it. In a private meeting, former President Carter's national security adviser, Zbigniew Brzezinski, tried to convince party skeptics that the bill was their best chance at ending the war.

Max Cleland, a Vietnam War veteran and former Democratic senator from Georgia, also came out in support of the bill. His endorsement could help to persuade more conservative Democrats who do not want to tie the hands of military commanders.

Like the House bill, the Senate legislation would allow for an unspecified number of troops to be left behind in Iraq for anti-terrorism missions, training Iraqi forces and protecting coalition infrastructure and personnel. Of the more than 140,000 U.S. troops in Iraq, fewer than half are combat forces.

The Senate proposal would urge the Iraqi government to meet certain benchmarks, such as disarming militias and amending the constitution to protect Sunni minorities.

The inclusion of the benchmarks was enough to persuade Nelson to support the bill, spokesman David DiMartino said. Nelson opposes arbitrary deadlines to end the war but wanted legislation that would put pressure on the Iraqi government to take more responsibility.

The Senate measure would set no consequences if the Iraqis fail to achieve those goals. Under the House bill, combat troops would have to begin coming home as early as this fall if the president cannot certify that the Iraqi government was making progress.

The Senate measure requires the U.S. commander in Iraq to submit regular reports on progress made by the Iraqi government toward meeting those goals; the president also would have to report on progress made in redeploying troops.