WASHINGTON (Reuters) - Senate Democrats filed a motion 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 on President Barack Obama's pick to head the Pentagon.

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.

Harry Reid, the Democratic Senate Majority leader, filed the motion to end debate after Republicans refused to give unanimous consent to allow a confirmation vote.

(Reporting By Thomas Ferraro and Patricia Zengerle; Editing by Sandra Maler)