A former federal judge appointed to oppose the U.S. Justice Department’s bid to drop the case against Michael Flynn said Wednesday the trial court should reject the move and instead proceed with sentencing the former Trump national security adviser, who has twice pleaded guilty to lying to the FBI.

John Gleeson, now a partner at Debevoise & Plimpton, was appointed last month to counter the Justice Department’s extraordinary retreat from the prosecution and also address whether Flynn’s judge should begin a perjury inquiry. Gleeson on Wednesday recommended against a stand-alone perjury investigation, instead advising the trial judge, U.S. District Judge Emmet Sullivan of the District of Columbia, to consider Flynn’s statements at sentencing.