House Democrats moved closer to crafting a resolution criticizing President Bush’s troop buildup in Iraq, as several senators threatened to attach a similar measure to any bill that comes to the Senate floor.

In the House, Democratic leaders huddled Wednesday in the office of Speaker Nancy Pelosi, D-Calif., over a draft of a non-binding measure that would allow the House an up-or-down vote on Bush’s increase of 21,500 troops in Iraq. Aides said the Democratic resolution, as currently drafted, is silent on whether Congress should fund the troop buildup, sidestepping that controversial issue for now.

The question of funding, however, could resurface Thursday morning, when the Democratic Caucus is scheduled to meet to discuss the measure as well as a schedule for considering it.

Indeed, as Democratic leaders worked on the non-binding resolution, other House Democrats discussed tougher moves, including ones that would use Congress’ power of the purse to set conditions on the buildup, block it and, in some cases, bar funding for any U.S. involvement in Iraq.

Even some Democrats who do not want the non-binding resolution to advocate cutting funding for the troop increase suggested that a more forceful action could be possible in the weeks ahead.

The Senate, meanwhile, remained stymied over how to proceed on its own non-binding Iraq resolution. Late Wednesday, John W. Warner, R-Va., rose on the Senate floor to warn that he and six other Republicans moderates would seek to attach his resolution (S Con Res 7), which opposes the troop increase, as an amendment to any bill that comes before the full chamber.

The warning was in a letter that was also signed by Olympia J. Snowe and Susan Collins of Maine, Chuck Hagel of Nebraska, Norm Coleman of Minnesota, Gordon H. Smith of Oregon and George V. Voinovich of Ohio.

“We will explore all our options under the Senate procedures and practices to ensure a full and open debate on the Senate floor,” the letter said.

Wednesday’s maneuvering on both sides of the Capitol came as polls underscored voters’ disenchantment with the war and their desire for Congress to do something about it. But Democrats remained torn about precisely what that action should be.

House Democratic leaders have said they plan to take their first steps on the issue next week by debating the non-binding resolution on the floor. It is unclear whether a committee would mark it up or hold a hearing on it before then. And it is uncertain whether Democrats can agree on its language.

“They are not there yet,” said John P. Murtha, D-Pa., chairman of the House Appropriations Defense Subcommittee, as he left the meeting Wednesday evening.

Murtha is among those advocating action beyond the non-binding measure. He would like to tie funding for the Iraq War in the fiscal 2007 supplemental to the Pentagon’s meeting certain requirements for military readiness. He also has advocated redirecting money in that bill from the troop increase toward restoring and replacing degraded military equipment. The full committee plans to mark up the supplemental in mid-March.

“After the Iraq supplemental, any surge the president attempts without congressional authorization will be unsustainable,” James P. Moran of Virginia, another Democrat on the Defense spending panel, said in an interview Wednesday. “They will have to revise their plans.”

Moran added that he plans to promote legislation that would require by year’s end a congressional reauthorization of the use of force in Iraq before “one more penny” is spent there. Another House appropriator, David E. Price of North Carolina, has filed a bill (HR 645) that would terminate the 2002 authorization for force (PL 107-243) in Iraq by year’s end.

Still other Democrats on the Appropriations Committee want to go further than Murtha. They are backed by a large bloc of Democrats in the Out of Iraq Caucus, which numbers 75 members and delegates, including several appropriators. Those ardent opponents of the war have backed a number of bills.

For instance, Edward J. Markey of Massachusetts has filed a bill (HR 353) that would prohibit funding for a troop increase beyond the level in Iraq on Jan. 9, 2007.

Jesse L. Jackson Jr. of Illinois said Wednesday he favors not using funds in the fiscal 2007 supplemental “for escalation purposes” and would seek to add language to the bill capping the number of troops in Iraq at the Jan. 1, 2007, level.

Jim McGovern of Massachusetts, a Democratic member of the Rules Committee, has proposed a bill (HR 746) that would require a withdrawal of U.S. troops within six months and bar any funding for the war thereafter. Three appropriators — Barbara Lee of California, John W. Olver of Massachusetts and José E. Serrano of New York — have cosponsored McGovern’s resolution.

Another Democrat, Henry A. Waxman of California, chairman of the House Oversight and Government Reform Committee, said Wednesday he advocates cutting off funds for the surge.

A substantial bloc of Democrats, though reticent about the funding issue in the non-binding resolution, seems open to considering it later. “I think it’s likely down the road,” said Martin T. Meehan of Massachusetts, a senior member of Armed Services.

George Cahlink and Martin Kady II contributed to this story.