WASHINGTON - Just hours after floating the idea of cutting $20 billion from President Bush's $142 billion request for military operations in Iraq and Afghanistan next year, Senate Budget Committee Chairman Kent Conrad, D-N.D., was overruled by fellow Democrats on Thursday.

"It's nothing that any of us are considering," Senate Majority Leader Harry Reid, D-Nev., told reporters.

Conrad's trial balloon to cut war funding would have affected the budget year beginning Oct. 1 and was separate from the ongoing debate over Bush's $100 billion request for immediate supplemental funding for Iraq and Afghanistan.

Even the Pentagon acknowledges that its $142 billion 2008 war funding request is simply a best guess of Iraq and Afghanistan costs, and Conrad's proposal didn't earn rebukes from Budget Committee Republicans.

But the speed with which it was rejected by his colleagues seemed to reflect Democrats' sensitivity to any accusations of giving shortshrift treatment to funding for troops in battle.

"Our caucus feels strongly that we should go with the president's numbers" on 2008 war costs, Conrad said. He spoke just hours after floating the idea of curbing Bush's request for next year's war budget.

The North Dakota Democrat said he was simply seeking to come up with the most accurate figures possible for war costs as he develops a Democratic budget blueprint for the fiscal year beginning Oct. 1. The $20 billion cut was based on Congressional Budget Office estimates - instead of the administration's February budget request - of Iraq and Afghanistan war costs.

The administration asked for $141.7 billion for fiscal 2008, but assumes only $50 billion for 2009 and no war funding after that.

CBO issued an estimate last month that forecasts 2008 costs of $120 billion for Pentagon operations in Iraq and Afghanistan and military aid for the armies of those two countries. The estimates would drop to $75 billion in 2009 and to $40 billion in 2010.

The CBO scenario assumes the number of troops deployed in Iraq and Afghanistan are reduced to 30,000 by 2010.

Even before restoring the proposed cut for 2008, Conrad's budget plan assumed $85 billion more in war funds than Bush requested. That's because Conrad included money for a continued troop presence over 2010-12.

"We are going to provide actually more funding, because we think the president's budget has understated the war costs over the five-year period," Conrad had said at the time he broached the idea of slashing $20 billion from the budget request.

Conrad added that the congressional budget resolution he is drafting for debate later this month will provide Bush's request for a $49 billion boost - to $481 billion - in the core Pentagon budget.

The annual congressional budget blueprint sets guidelines but is not binding, and the actual war budget will be set under a fiscal 2008 defense spending bill that will advance later this year.

Also on Thursday, House Democratic leaders coalesced around legislation that would require troops to come home from Iraq within six months if that country's leaders fail to meet promises to help reduce violence there.

The plan would retain a Democratic proposal prohibiting the deployment to Iraq of troops with insufficient rest or training or who already have served there for more than a year. Under the plan, such troops could only be sent to Iraq if President Bush waives those standards and reports to Congress each time.

The proposal is the latest attempt by Democrats to resolve deep divisions within the party on how far to go to scale back U.S. involvement in Iraq. Rep. James Moran said the latest version has the support of party leadership and said he believes it is final and has the best chance at attracting broad support.

"We're going to report out" a war spending bill "that's responsive to the will of the voters last November and brings our troops home as soon and safely as possible," Moran, D-Va., said in an interview Thursday.

Moran, a member of the House committee that oversees military spending, said the plan was discussed in a closed-door meeting of committee Democrats on Thursday.

Brendan Daly, a spokesman for House Speaker Nancy Pelosi, D-Calif., declined to confirm the details and or say whether Pelosi backs the plan. But he said: "We have said we want to make sure our troops have all the training and equipment they need and that the Iraqi government must meet the benchmarks President Bush endorsed."

The Senate could begin floor debate on Iraq as early as next week. Sens. Joseph Biden, D-Del., and Carl Levin, D-Mich., have proposed a resolution that would call for combat troops to come home by March 2008.