The top Senate Democrat on Thursday made a dramatic bid to smash Republican resistance blocking the confirmation of Chuck Hagel as the next US defense secretary, but the gambit looked likely to fail.
Senate Democratic Majority leader Harry Reid suddenly called a procedural vote on the nomination at 4:15 pm (2115 GMT) but appeared likely to fall short of the 60-vote super-majority in the 100-seat Senate needed to prevail.
A defeat would not doom Hagel's nomination to lead the Pentagon in President Barack Obama's second term, but would leave him in limbo while the Senate takes a week-long recess.
Republicans had blocked Reid's previous attempts to bring Hagel's nomination up for a vote on the Senate floor, demanding more details on his finances and on Obama's management of a September attack on the US consulate in Benghazi.
Later, Republicans delaying Hagel's nomination said they were ready to drop their blocking tactics, but only after the recess, frustrating White House demands for a vote by the end of this week.