Updated: 8:08 p.m.

Sens. Joe Lieberman (ID-Conn.) and Susan Collins (R-Maine) vowed not to end their efforts to repeal the military’s ban on gay service members after bipartisan talks broke down Thursday afternoon.

“It ain’t over till it’s over. We’ve got the 60 votes, and we’re going to keep fighting,” Lieberman said after the Senate rejected a procedural motion, 57-40, to consider the defense authorization bill, which contains language to repeal “don’t ask, don’t tell.”

Collins was the lone Republican to vote in support of the motion, but it fell short of the 60 votes needed to move forward. Freshman Sen. Joe Manchin of West Virginia was the only Democrat to vote against it.

At a news conference after the floor vote, Lieberman and Collins appeared distraught and frustrated that Majority Leader Harry Reid (D-Nev.) moved forward with a vote, trumping bipartisan talks to determine a way to pass the defense measure before the Senate adjourns for the year, likely on Dec. 17.

Reid explained on the floor that he decided to bring up the floor vote because he was unable to reach consensus with Republicans. “It doesn’t matter what I do,” he said of the bipartisan talks. “Before I get to the end of it, they change the rules again.”

Reid alleged that Collins, who has been negotiating with the Majority Leader since last week, was advocating for unlimited debate that would in effect derail passage of the defense bill before year’s end. In an interview with Roll Call, Collins countered that argument, saying she wanted a week of floor time to consider the defense bill, which in past years has taken about 11 days to complete.

“It is not true that I demanded to have unlimited debate on the bill. As Joe Lieberman will verify, the first offer that I made was for a week to debate the bill,” the Maine Republican said.

Collins said she had been working with Reid to “put together an agreement that would allow us to get the 60 votes.” A handful of key moderates, including GOP Sens. Scott Brown (Mass.) and Lisa Murkowski (Alaska), voted against the procedural motion Thursday, citing frustration with the process on the floor.

“Nothing was offered in terms of a reasonable process and reasonable amendments. I’m sorry we’re at this point, but I think he had a path forward and he chose not to do it,” Murkowski said of Reid. “He chose to close the door, and I think it’s unfortunate.”

Gay rights organizations lambasted Republicans for obstructing the defense bill. They hailed Lieberman and Collins’ move to push a stand-alone repeal measure, which both chambers would have to pass and which Reid told Lieberman he would co-sponsor. The House passed its own defense bill, which included the DADT repeal language, in May.

Senate Democrats also sought to place blame squarely on the GOP, arguing that it held up not only a repeal of DADT but also pay raises and benefits for troops. Sen. Mark Udall (D-Colo.) has called for the Senate to work past Dec. 17 to complete action on the defense bill, although Armed Services Chairman Carl Levin (D-Mich.) issued a statement acknowledging that the path forward is grim.

“I also believe that it is vitally important to our national security to pass a Defense Authorization Act,” Levin said. “I will continue to explore paths that could lead to that goal, though given the limited amount of time left in this Congress, that may be too high a mountain to climb.”

A host of legislative priorities remain for the Senate to consider in the week the chamber is slated to be in session. Reid is expected to put forward an extension of Bush-era tax cuts in the coming days and to move on a continuing resolution to keep the government funded next year. Republicans have maintained they would not allow action on any other bills until those two measures were approved. The White House is also passionately advocating for the Senate to adopt the new Strategic Arms Reduction Treaty before year’s end, which requires 67 votes for ratification.