The deputy director of the US Consumer Financial Protection Bureau late on Sunday filed a lawsuit seeking to halt President Donald Trump from naming an official to run the watchdog agency on an interim basis.

Leandra English, who was named acting director by outgoing agency chief Richard Cordray on Friday, is seeking a temporary restraining order barring Mick Mulvaney, Trump’s head of the Office of Management and Budget, from taking control of the agency as Trump had sought.

The suit, filed in US District Court in Washington, argues that Trump overstepped his legal authority in attempting to place Mulvaney in the post, maintaining Cordray had legal grounds to name his successor until a full-time director is named by Trump and confirmed by the Senate.