A Democratic-led House panel on Wednesday approved a measure to hold U.S. Attorney General William Barr in contempt for refusing to hand over an unredacted copy of the Mueller report on Russian election interference even as President Donald Trump invoked the legal principle of executive privilege to block its disclosure.

Throwing down another challenge to Trump, the House of Representatives Judiciary Committee voted to recommend that the full House cite Barr, the top U.S. law enforcement official and a Trump appointee, for contempt of Congress after he defied its subpoena for the complete report and underlying evidence.

The confrontation escalated a constitutional clash between the Democratic-controlled House and Republican president over congressional powers to investigate him, his administration, his family and his business interests.