WASHINGTON — The Democratic-controlled House defeated legislation yesterday to require the withdrawal of American combat troops from Iraq within nine months, then pivoted to a fresh challenge of President Bush’s handling of the unpopular war. The vote on the nine-month withdrawal measure was 255–171.

On a day of complex maneuvering, Democrats said they would approve legislation funding the war on an installment plan and Mr. Bush said he would veto it. But the president, under pressure from lawmakers in both parties, coupled his threat with an offer to compromise on a spending bill that sets standards for the Iraqi government.

“Time’s running out, because the longer we wait the more strain we’re going to put on the military,” said Mr. Bush, who previously had insisted on what he termed a “clean” war funding bill.

Despite Mr. Bush’s ability to sustain his vetoes in the House — as demonstrated last week — critics of the war insisted on challenging him anew.

“This war is a terrible tragedy and it is time to bring it to an end,” Rep. James McGovern, leading advocate of the bill to establish a nine-month withdrawal timetable, said. “For four long, deadly years, this administration and their allies in Congress have been flat wrong about Iraq,” said the Massachusetts Democrat.

Republicans argued that a withdrawal would be disastrous. “Now is not the time to signal retreat and surrender. How could this Congress walk away from our men and women in uniform,” Rep. Jerry Lewis, a Republican of California, said.

Mr. Bush’s critics in Congress treated his willingness to apply benchmarks to the Iraqis as a concession, but said they wanted more. “Democrats are not going to give the president a blank check for a war without end,” the House speaker, Rep. Nancy Pelosi of California, said.

To buttress her point, Democrats advanced legislation for a vote later in the evening to provide funds for the war in two installments. The first portion would cover costs until August 1 — $42.8 billion to buy equipment and train Iraqi and Afghan security forces.

Under the bill, it would take a summertime vote by Congress to free an additional $52.8 billion, the money needed to cover costs through the September 30 end of the fiscal year. “We reject that idea. It won’t work,” the president declared after a meeting with military leaders at the Pentagon.

Democratic officials, speaking privately, said Ms. Pelosi had agreed to allow the vote on the withdrawal measure in the hope that her rank-and-file would then unite behind the funding bill.

But in an increasingly complex political environment, even that measure was deemed to be dead on arrival in the Senate, where Democrats hold a narrow advantage and the rules give Republicans leverage to block legislation.

The majority leader, Senator Reid, a Democrat of Nevada, has met privately in recent days with White House Chief of Staff Josh Bolten and the Senate Republican leader, Senator McConnell of Kentucky, the beginning of talks aimed at producing a compromise funding bill that the president would sign. Both Mr. Bush and the Democratic leaders were maneuvering in complicated political environment.

[House Republican moderates, in a remarkably blunt White House meeting, warned President Bush this week that his pursuit of the war in Iraq is risking the future of the Republican Party and that he could not count on GOP support for many more months, reports The Washington Post.

The meeting, between 11 House Republicans, Mr. Bush, Secretary of State Rice, Defense Secretary Gates, White House political adviser Karl Rove, and White House press secretary Tony Snow, which ran for an hour and a half Tuesday afternoon, was perhaps the clearest sign yet that patience in the party is running out. The meeting, organized by Rep. Charlie Dent, a Republican of Pennsylvania, one of the co-chairmen of the moderate “Tuesday Group,” included Reps. Tom Davis, a Republican of Virginia, Michael Castle, a Republican of Delaware, Todd Platts, a Republican of Pennsylvania, Jim Ramstad, a Republican of Minnesota, and Jo Ann Emerson, a Republican of Missouri.

“It was a very remarkable, candid conversation,” Mr. Davis said. “People are always saying President Bush is in a bubble. Well, this was our chance, and we took it.”

Participants said frustration about the Iraqi government’s efforts dominated the conversation, with one pleading with the president to stop the Iraqi parliament from going on vacation while “our sons and daughters spill their blood.” The House members pressed Messrs. Bush and Gates hard for a “Plan B” if the current troop increase fails to quell the violence and push along political reconciliation. Mr. Davis said administration officials convinced him there are contingency plans, but that the president declined to offer details, saying that if he announced his backup plan, the world would shift its focus to that contingency, leaving the current strategy no time to succeed.

Mr. Davis, a former chairman of the National Republican Congressional Committee, also presented Mr. Bush dismal polling figures to dramatize just how perilous the party’s position is, participants said. Mr. Davis would not disclose details, saying the exchange was private. Others warned Mr. Bush that his personal credibility on the war is all but gone.

Mr. Snow, who sat in on the meeting in the president’s private quarters, said it should not be overdramatized or seen as another “marching up to Nixon,” a reference to the critical moment during Watergate in 1974 when key congressional Republicans went to the White House to tell President Nixon that it was time to resign.

“This is not one of those great cresting moments when party discontents are coming in to read the president the riot act,” he said. But Mr. Snow acknowledged that the meeting included some blunt, if respectful, discussion.]

Ms. Pelosi and Mr. Reid face obstacles of their own. They are determined to make sure that essential funding for the war is not cut off. At the same time, they are laboring to keep faith with their own rank-and file, with the war-weary voters who installed them in power, and with MoveOn.org and other groups whose overriding goal is to force the withdrawal of the American combat troops.