A day after he asked Democrats to schedule a vote this month to repeal a ban on openly gay service members, Sen. Joe Lieberman called on Majority Leader Harry Reid to delay a vote on the issue scheduled for Wednesday evening to allow for more time to negotiate a deal with moderate Republicans on the measure.

The Connecticut Independent has been working with Sen. Susan Collins (Maine), the lead Republican in favor of the repeal, to garner the 60 votes needed to pass the defense authorization measure that includes a repeal of “don’t ask, don’t tell.” The Nevada Democrat scheduled a vote for Wednesday night to consider that bill, but Lieberman told reporters earlier Wednesday that Collins’ support hinges on having extended debate time and an agreement on amendments. The three Senators discussed the matter on the floor earlier Wednesday, but those talks did not yield a time agreement.

“I think we’re exchanging ideas and I just really hope Sen. Reid will not bring up the motion to reconsider until we’ve discussed a fair and open amendment process, because if we do, we have the votes,” Lieberman told reporters.

Like Collins, a handful of other moderate Republicans have indicated their support but want the Senate to first pass an extension of Bush-era tax cuts. Sen. Scott Brown (Mass.) said last week that he would vote for repeal, but Collins is the only GOPer negotiating with Reid on the matter. Most Democrats favor a repeal of the military policy enacted in 1993 under President Bill Clinton, although Sens. Joe Manchin (W.Va.) and Jim Webb (Va.) have not said how they would vote.

Reid is juggling a handful of year-end priorities, and according to one Democratic source, the defense measure is the one that is ripe for floor time. A tax cut bill will not be ready until next week, and Foreign Relations Chairman John Kerry (D-Mass.) said earlier Wednesday that ratification of the Strategic Arms Reduction Treaty would also not come up until next week, if at all, before the Senate adjourns for the year. But Republicans have said they will not support moving forward on any bill until the Senate approves the tax cuts and a continuing resolution to keep the government funded next year. The Senate is scheduled to adjourn Dec. 17.

“Obviously, Sen. Reid has many points of pressure on him to get things done before the 17th,” Lieberman said.

The Democratic source also said Reid offered Collins floor time to allow for 15 amendments to the defense measure, with 10 of those slated for Republican Members. The aide said Collins demanded an open amendment process, but such an agreement could threaten the passage of the DADT provisions because several Republicans, led by Sen. John McCain (Ariz.), might offer endless amendments on the floor to prevent the bill’s passage.

The Senate failed to pass a motion to proceed to the defense bill in August, and Reid is set to bring that motion up again Wednesday evening. With Collins’ support in doubt, he is likely to again fall short of the 60 votes needed to proceed. A failed vote Wednesday night would be “a real body blow to the whole effort to get this done,” Lieberman said.

Lieberman has also called on Reid to keep the Senate in session past Dec. 17 in order to make time to consider the defense bill.