Attorney General Maura Healey and her counterparts from other states are backing a legal challenge to the leadership of the Consumer Financial Protection Bureau, arguing that President Donald Trump’s appointment of an acting director will hinder the agency’s independence and effectiveness.

Richard Cordray, the CFPB’s first director, stepped down from his post in late November after six years at the helm of the bureau charged with protecting consumers from unfair or deceptive financial practices.

Trump named his budget director, Mick Mulvaney, as the new acting director, and deputy director Leandra English filed a lawsuit seeking to halt his appointment, pointing to the law establishing the bureau, which says the deputy director should fill the top job until the Senate confirms a replacement.

Healey on Friday joined 17 other attorneys general on an amicus brief supporting English, saying it’s crucial to keep the CFPB independent and its succession plan aims to ensure that autonomy.

“Attempts to dismantle Congress’s careful and concerted efforts in structuring the CFPB as a truly independent agency would, if successful, harm the Amici States’ ability to enforce the many consumer financial laws that protect their residents,” the brief said.