The top Democrat on the Senate Judiciary Committee is demanding that acting Attorney General Matthew Whitaker and fired Attorney General Jeff Sessions be called in for congressional hearing “as quickly as possible.”

“The circumstances surrounding Attorney General Sessions’ departure raise serious questions, including whether the appointment is lawful and the possible impact on Special Counsel Mueller’s investigation,” Senate Judiciary Committee Ranking Member Dianne Feinstein, D-Calif., said in a letter sent Tuesday to Chairman Chuck Grassley, R-Iowa, demanding a hearing with Whitaker.