U.S. Senate Democrats filed a motion on Wednesday to end debate on the nomination of Chuck Hagel as President Barack Obama's new secretary of defense, setting up a showdown vote by Friday.
Democrats are expected to muster the 60 votes needed in the 100-member chamber to clear a Republican procedural roadblock, clearing the way for a vote on his confirmation.
Once the roadblock is cleared, Hagel is expected to win the simple majority of Senate votes he needs to be confirmed.
Democrats control 55 seats in the Senate and none has come out against Hagel, a former Republican senator from Nebraska who has faced fierce opposition from members of his own party.
Some Republicans have raised questions about whether Hagel, 66, was sufficiently supportive of Israel, tough enough on Iran or capable of leading the Pentagon.
At least two of the 45 Republicans in the chamber have said they would vote for Hagel's confirmation, and several others have said they would not support a procedural tactic to block or delay a vote.
Harry Reid, the Senate Democratic leader, filed the motion to end debate after Republicans refused to give unanimous consent to allow a vote on Hagel's confirmation.
"It's the first time in the history of our country that a presidential nominee for secretary of defense has been filibustered," Reid said. "What a shame. But, that's the way it is."
After more than two hours of often intense debate, the Senate Armed Services Committee voted 14-11 along party lines on Tuesday to advance Hagel's nomination to succeed Leon Panetta as the civilian leader at the Pentagon.