The top Democrats in the U.S. House of Representatives and Senate on Thursday called on Special Counsel Robert Mueller to testify publicly about his investigation into Russian meddling in the 2016 election and whether the Trump campaign colluded with Russia.

House Speaker Nancy Pelosi and Senate Democratic leader Chuck Schumer criticized Attorney General William Barr for writing what they called a “slanted” summary letter and for planning a press conference to immediately follow the expected release of the report detailing the probe’s findings on Thursday.

“We believe the only way to begin restoring public trust in the handling of the Special Counsel’s investigation is for Special Counsel Mueller himself to provide public testimony in the House and Senate as soon as possible,” Pelosi and Schumer said in a statement. (Reporting by Makini Brice Editing by Chizu Nomiyama)