Facing tight time constraints to pass an Iraq War funding measure before the Memorial Day recess, Senate Democratic and Republican leaders are seriously considering passing a “placeholder” bill that could move quickly through the Senate and get them to conference with the House before the end of this week.

“Once we get into conference, the real negotiation occurs between the House, the Senate and the White House,” said Jim Manley, spokesman to Senate Majority Leader Harry Reid (D-Nev.).

While Manley confirmed on Friday that passing a placeholder bill was one option in discussion, he cautioned that a lot of work is still going on behind the scenes to craft a suitable Senate bill.

“Don’t underestimate the amount of work that’s going into getting something on the Senate floor,” he noted. He added that Senate Minority Leader Mitch McConnell (R-Ky.) and Reid are “still talking about the process.”

Manley said Reid and McConnell were expected to continue their talks over the weekend about how to craft a procedural time agreement — as well as an actual bill — that would get the measure quickly to conference, rather than having a protracted debate or amendment process on the Senate floor.

The discussions have included the idea of passing a shell bill that does not have any language in it or a measure that is not necessarily a war spending bill, both Democratic and Republican aides said.

The Bush administration is pushing the notion of passing a shell, said one Senate GOP aide.

But as a Senate Democratic aide pointed out, the placeholder strategy has its pitfalls.

“That strikes me as something that would be politically difficult,” said the aide, who requested anonymity in order to speak frankly about Senate deliberations. “The problem is you don’t go into conference with a strong bill to deal with the House. You almost go into conference with no position at all. … I don’t see it working.”

Still, the Democratic aide noted that Reid has not been lying when he’s claimed that “everything is on the table.”

“At the end of the day, if [a placeholder bill] gets 60 votes and everything else gets 55, then that’s what you do,” the aide said, referencing the 60 votes needed to overcome any potential GOP-led filibuster.

But it appears that Senate Democrats are right to be nervous about heading into conference with the House.

Even as the House leaders touted their Thursday victory in passing a controversial second version of the war spending bill, Democratic sources suggested Friday the outcome of another vote — on a measure that would have dictated the immediate withdrawal of forces from Iraq — would provide House lawmakers with leverage when the chambers meet in conference.

Although the House ultimately defeated the separate withdrawal proposal, 255-171, Democratic aides assert that support for the measure far exceeded expectations, even among liberal lawmakers who had agitated for the bill.

“There’s no question that the votes on Thursday strengthened our position and gave us a few extra chips,” said one Democratic aide.

Democratic leaders agreed last week to move the new withdrawal proposal, authored by Rep. Jim McGovern (D-Mass.), as a concession to liberal lawmakers who had offered only a lukewarm reception to the newest version of the emergency supplemental, which would fund the war through July and require Congress to vote again in order to release the remainder.

“At the end of the day, this shows there are certainly a number of voices that are pushing for something stronger. … This forces [leadership] to take into consideration that the progressive wing of the party is lock step with the American public,” said an aide to one antiwar Democratic lawmaker.

The outcome of the Thursday vote could embolden the Progressive Caucus in its efforts to preserve the House position in conference, which many had expected would be watered down.

But a Democratic leadership aide acknowledged that while the vote could “strengthen the House’s hand in a conference,” it does not erase other hurdles.

“That will bump up against the reality of the Senate needing 60 votes to move anything and also the presidential veto,” the aide said.

In the Senate, negotiations have centered on how to get the 60 or more votes for a strong response to the president’s veto of the first war spending bill, which would have set a goal of ending combat operations in Iraq by next year. That bill garnered only 51 votes.

Both Democrats and Republicans say they are united in seeking to include “benchmarks” for the Iraqi government, but they remain deeply divided — including within their own parties — over whether and how to impose consequences on the Iraqis or the Bush administration for any failure to meet those benchmarks.

Sen. John Warner (R-Va.) continues to work on a proposal he hopes could become the vehicle for compromise in the Senate. But his spokesman, John Ullyot, said, “it is still too early to say what form [the proposal] will take.”

The Warner proposal would likely set benchmarks for the Iraqi government as well as strict requirements for the Bush administration to brief Congress on progress. But because Warner has essentially ruled out any hard consequences for the Iraqi government’s lack of progress or the failure of Bush’s military “surge” plan, he may have trouble getting a broad swath of the Senate to sign on.

“Warner might be the best chance [for compromise] because he has so much credibility on this, but I don’t think Democrats will go for that because it doesn’t have enough teeth,” predicted one well-positioned Senate GOP aide.

That aide said Sen. Olympia Snowe’s (R-Maine) proposal with Sen. Evan Bayh (D-Ind.) might have a better chance of moving.

Snowe said Thursday that she has concocted “an interesting blend in this proposal,” noting that her idea would force the White House to at least come up with a plan to begin a phased redeployment of forces but would not force the administration to adopt such a plan within any specific time frame.

Additionally, Senate aides said there have been discussions of requiring Bush to come to Congress in September for another “use of force” resolution. The current resolution, under which Bush took the country to war with Iraq, would expire, one aide said, and Congress could lay out a new mission that would not include combat but instead have U.S. troops in Iraq aid in the training of Iraqi forces.