A federal judge on Thursday rejected President Donald Trump’s maneuvering to keep Alina Habba in place as New Jersey’s top federal prosecutor, ruling that she has been serving without legal authority since July 1, and teeing up a potentially broader constitutional fight if the administration decides to appeal.

In a 77-page opinion, United States District Judge Matthew Brann wrote that Habba “is not lawfully holding the office of United States Attorney” and therefore cannot continue overseeing prosecutions as the acting U.S. attorney. The Trump administration had used a series of contested legal tactics to extend Habba’s tenure after her 120-day interim appointment expired.