(Bloomberg) — Top Democrats demanded that Acting Attorney General Matthew Whitaker recuse himself from Special Counsel Robert Mueller’s investigation, citing hostile statements toward the probe and alleging he has multiple conflicts of interest. In an emailed letter to Assistant Attorney General Lee Lofthus, the Department of Justice’s chief ethics official, House and Senate lawmakers said Whitaker’s past statements “indicate a clear bias against the investigation,” and that his relationship with a grand jury witness in the probe raises “additional concerns about his ability to supervise the investigation independently and impartially.” The lawmakers, including Senate Democratic Leader Chuck Schumer, House Democratic Leader Nancy Pelosi, Senate Judiciary Committee Ranking Member Dianne Feinstein and House Judiciary Committee Ranking Member Jerrold Nadler, demanded that Lofthus immediately tell them whether he’s advised Whitaker to step aside on the Mueller investigation. Power to Halt Whitaker has come under increasing scrutiny for openly criticizing Mueller’s Russia investigation in the past because he now has the power to hobble or halt the probe.