Washington ? House Democratic leaders have 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, party officials said Thursday.

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 thinks 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 Thursday in a closed-door meeting of committee Democrats.

Brendan Daly, a spokesman for House Speaker Nancy Pelosi, D-Calif., declined to confirm the details 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.”

Bush said the Iraqis had promised to meet certain goals when he offered to send 21,500 more troops to Iraq. For example, the Iraqis pledged to spend more money on reconstruction and reach a political agreement to share the nation’s oil resources.

If the Iraqis fail to live up to the promises, some U.S. troops could be left behind to train Iraqi troops or conduct counterterrorism missions, Moran said.

Bush requested $93.4 billion for this year’s military operations in Iraq and Afghanistan.

Moran said that as of Thursday, the proposal was on track to add $1 billion to step up efforts in Afghanistan. Money also would be added to improve health care for veterans and help wounded active-duty troops, as well as provide relieve for hurricane victims.

The Senate, meanwhile, 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.

As Democrats finalized their spending plan for this year, White House chief of staff Joshua Bolten told Senate Republican leaders that the administration will need additional funding to pay for the influx of troops to Iraq.

The Pentagon initially estimated the 21,500 troops would cost $5.6 billion through Oct. 1. But 6,000 more personnel will be needed to provide support to the combat units, according to GOP aides.

Also Thursday, an influential Senate Democrat floated the idea of cutting $20 billion from Bush’s request for military operations next year in Iraq and Afghanistan, only to be swiftly overridden by his colleagues.

The trial balloon floated by Budget Committee Chairman Kent Conrad would have trimmed Bush’s $142 billion war budget for 2008 by about one-seventh.