Senate Minority Leader Chuck Schumer (D-NY) speaks to the media after a Senate Democratic Caucus lunch on Capitol Hill in Washington, U.S., February 5, 2019. REUTERS/Joshua Roberts

WASHINGTON (Reuters) - In unusually harsh language, Senate Democratic leader Chuck Schumer said on Thursday that if President Donald Trump declares a national emergency to build a border wall, he would be committing “a lawless act” and warned that Congress would take steps to stop him.

“Declaring a national emergency would be a lawless act, a gross abuse of the power of the presidency,” Schumer said in remarks on the Senate floor. He added that Trump would be committing “naked contempt for the rule of law and congressional authority.”