Federal Reserve Gov. Lisa Cook filed a lawsuit on Thursday saying President Donald Trump has no power to remove her from office, setting up a legal battle that could challenge long-established norms for the U.S. central bank¡¯s independence.

The lawsuit said Trump violated a federal law allowing him to remove a Fed governor only ¡°for cause¡± when the president took the unprecedented step on Aug. 25 of announcing he would fire her.

Trump has accused Cook of committing mortgage fraud in 2021, a year before she joined the central bank¡¯s governing body.