Senate Democratic and Republican leaders have agreed to approve a “placeholder” bill on Iraq that contains no funding for U.S. troops and will punt the development of a compromise with the White House to a House-Senate conference committee on the multibillion-dollar Iraq War spending measure.

To quickly begin conference negotiations on the supplemental spending bill, Senate Majority Leader Harry Reid (D-Nev.) said Tuesday that he and Minority Leader Mitch McConnell (R-Ky.) will jointly introduce a measure that “would be something we can pass for sure and get to conference” after a Senate vote on the bill, which is now slated for Thursday.

Though the House passed a bill last week that would give President Bush only partial war funding until another Congressional vote in July, Reid and McConnell have been negotiating with White House Chief of Staff Josh Bolten on how to set benchmarks for success in Iraq, a process that likely will continue during conference talks with the House. Bush vetoed the first war spending bill Congress sent him because it included a goal for withdrawing troops from Iraq by next spring.

Senators and aides said the language in the placeholder measure likely would mirror a nonbinding resolution authored by Sen. Patty Murray (D-Wash.) that passed the Senate, 96-2, on March 15. That resolution expressed the sense of the Senate that Congress and the president should take no actions to undermine the safety of U.S. troops or do anything to impact their ability to complete their assigned missions.

The move comes as Reid attempts to meet his self-imposed deadline to get a second war spending bill to Bush by Memorial Day.

On Monday, Reid tried to increase the pressure on negotiators and potential contrarians by threatening to keep the Senate in session beyond the scheduled weeklong Memorial Day recess.

“The Senate must complete action on the supplemental this week so it can be conferenced with the House and sent to the president prior to the scheduled Memorial Day recess,” Reid said on the floor. “It will occur. That is, the conference will be completed or we will delay our recess.”

But McConnell said Tuesday that he believes the war spending issue will be resolved in time for Members to take a much-needed break after eight weeks of uninterrupted work.

“I don’t think it’ll be necessary,” he said of the need to stay in town any longer.

House Majority Leader Steny Hoyer (D-Md.) told reporters Tuesday that he was “hopeful” the supplemental would be finished before the House adjourns for the Memorial Day recess, but he did not commit the House to action.

Hoyer acknowledged that it could be politically uncomfortable to leave for recess without a completed bill. “I think the American public would hold everybody accountable, as they should, for not doing that, but I will reiterate we passed a bill, [the president] vetoed it, we’re now trying to come back with a second bill,” he said.

One knowledgeable Democratic aide said it was “possible but unlikely” at this point that the House would delay the recess to work on the bill.

Meanwhile, Senate Democrats and Republicans appeared ambivalent about the idea of passing a placeholder instead of an actual war spending bill, but it appeared Tuesday that a majority in both parties have given Reid and McConnell the go-ahead.

“We all understand the two realities that are confronting us, and that is that we need to move quickly. And, second, the measure we consider in the Senate to go to conference will not be the final measure [and will be] subject to significant changes, and I think that’s the attitude and understanding that everyone has,” said Sen. Jack Reed (R.I.) of his fellow Democrats.

Sen. Frank Lautenberg (D-N.J.) said there is some concern among Democrats about how passing a placeholder will affect their ability to press the White House for additional emergency spending for domestic needs, such as hurricane aid, agricultural disasters, homeland security and children’s health care programs. The first war spending bill contained more than $20 billion in domestic spending.

For now, Republicans appear to be on board with the placeholder approach.

“Republicans can get behind anything that enables us to get to conference quickly,” said Sen. Richard Burr (N.C.). But he warned that the Senate Republican Conference is expecting Democrats and the White House to produce an actual compromise during those conference negotiations.

“If it doesn’t accomplish, in the right way, funding for the troops, we’ve got enough votes to block it,” he said.

Though Senate Democrats also are concerned about whether passing the Murray language will put them in a weak negotiating position with the House, Reid indicated that the four votes the Senate will take today on Iraq — albeit as part of debate on a water resources bill — will help illuminate the Senate’s position going into conference.

“The purpose of this, of course, is to make sure … that despite the president’s stubbornness, that we are fighting very hard to make sure that when we go to the conference we’re speaking from … a position of strength, not weakness,” Reid said.

The Senate is scheduled to vote today on two Democratic amendments: Sen. Russ Feingold’s (Wis.) proposal to cut off funding for the war if the mission is not changed to a largely anti-terrorism and support role, and Sen. Carl Levin’s (Mich.) amendment allowing the president to waive requirements that he begin redeploying troops out of Iraq by October. The Levin amendment is similar to but less restrictive than language included in the first supplemental that Bush vetoed.

Reid is co-sponsoring both amendments.

Republicans also will offer two Iraq-related amendments to the water resources bill. One, sponsored by Sen. John Warner (Va.), would require the Bush administration to brief Congress on the results of the “surge” strategy in July as well as authorize independent assessments of Iraq’s ability to govern itself.

Republicans had not decided what their second amendment would be as of press time. All four amendments must get 60 votes to be adopted on the bill, but it is unlikely that any of the known proposals would garner that much support.

Besides, any amendment that is adopted to the water resources bill likely will be dropped in a House-Senate conference committee.

Susan Davis contributed to this report.