US Federal Reserve Board member Lisa Cook brought a lawsuit against President Donald Trump Thursday, contending that he illegally tried to remove her.

Cook brought the suit in the US District Court for the District of Columbia after Trump attempted to fire her on Monday based on an allegation that Cook lied on a mortgage application. The complaint opened with a statement on the importance of the case:

This case challenges President Trump’s unprecedented and illegal attempt to remove Governor Cook from her position which, if allowed to occur, would the first of its kind in the Board’s history. It would subvert the Federal Reserve Act (“FRA”), which explicitly requires a showing of “cause” for a Governor’s removal, which an unsubstantiated allegation about private mortgage applications submitted by Governor Cook prior to her Senate confirmation is not.

While the president can fire many executive agency heads “at-will,” the Federal Reserve Act of 1913 allows the president to only remove members of the Federal Reserve Board “for cause.” This “for cause” standard is typically met when board members engage in misconduct or malfeasance. In Trump’s announcement of Cook’s firing, he stated he believed he had “good cause” to fire Cook.

One of the main responsibilities of Federal Reserve Board members is to participate in the Federal Open Market Committee (FOMC), which votes to set interest rates. In 2022, the Federal Reserve raised interest rates in response to increased inflation following the COVID-19 pandemic. Since then, interest rates have remained higher than the pre-pandemic rates, in part, some economists believe, because tariffs have kept inflation high. Despite this, Trump has battled with the Federal Reserve to lower interest rates, arguing the current course has slowed growth and hurt homebuyers. However, economists have warned that lowering interest rates may further accelerate inflation.

Trump’s firing attempt is in line with multiple removals of heads of various administrative agencies over the last six months. Commentators expect the case to reach the Supreme Court, where justices would likely weigh considerations of executive power and the president’s ability to define “good cause.”