A federal judge on Wednesday appointed Debevoise & Plimpton partner John Gleeson to oppose the Justice Department’s move to dismiss the prosecution of Michael Flynn, the former Trump national security adviser who twice pleaded guilty to lying to investigators about his past communications with the Russian ambassador to the U.S.

U.S. District Judge Emmet Sullivan selected Gleeson a day after signaling his interest in hearing outside views on the Justice Department’s sudden abandonment of the Flynn case, a move that renewed criticism that U.S. Attorney General William Barr was intentionally trying to undermine the special counsel’s Russia investigation and to interfere to protect an ally to President Donald Trump.