Rep. Maxine Waters said she may call Trump administration budget chief Mick Mulvaney to testify next year about his time running the Consumer Financial Protection Bureau, which she said led to "harmful" results for consumers.

Waters, D-Calif., is expected to chair the House Financial Services Committee next year and already has questions about how Mulvaney handled the agency.

“I am writing to inform you that while your time running the Consumer Bureau may be over, the time for accountability for your actions is about to begin,” Waters wrote in a letter addressed to Mulvaney, who leads the Office of Management and Budget and is expected to begin as acting White House chief of staff next month.

Waters accused Mulvaney of politicizing the consumer financial watchdog agency through his leadership staff appointments and slowing its enforcement of the financial service industry.

She also accused him of purposefully trying to weaken the agency, including by renaming it, in an effort to "reduce the public's awareness" of the role it plays in helping consumers keep large financial institutions in line.

“To that end, I look forward to your full and complete cooperation with the Committee's oversight work as we consider and review the actions of the Consumer Bureau at your direction,” writes Waters. “Please be advised that, as part of this important oversight work, you may be called before the Committee to testify regarding your tenure at the agency.”