Former White House counsel Don McGahn must comply with a congressional subpoena seeking his testimony about President Donald Trump¡¯s efforts to impede the now-completed federal investigation into Russian interference in the 2016 U.S. election, a judge ruled on Monday.

In an important case about presidential powers, U.S. District Judge Ketanji Brown Jackson in Washington rejected the Trump administration¡¯s legal claim that current and former senior White House officials cannot be compelled to testify before Congress.

McGahn, who left his post in October 2018, last May defied a subpoena from the Democratic-led House of Representatives Judiciary Committee for testimony. The subpoena was issued months before the House opened an impeachment inquiry in September into the Republican president¡¯s actions concerning Ukraine. The committee sued McGahn in August to try to enforce the subpoena.