WASHINGTON (AP) — A federal judge has ordered former White House counsel Donald McGahn to appear before Congress in a setback to President Donald Trump’s effort to keep his top aides from testifying.

The outcome could lead to renewed efforts by House Democrats to compel testimony from other high-ranking officials, including former national security adviser John Bolton.

Judge Ketanji Brown Jackson ruled Monday in a lawsuit filed by the House Judiciary Committee.

McGahn was a star witness in special counsel Robert Mueller’s investigation and Democrats wanted to question McGahn about possible obstruction of justice by Trump. That was months before the House started an impeachment inquiry into Trump’s effort to get Ukraine to announce an investigation of former Vice President Joe Biden.

An appeal is likely.