A divided appeals court ruled Wednesday that President Donald Trump doesn’t have the authority to unilaterally remove and replace the director of the U.S. Copyright Office.

A three-judge panel from the U.S. Court of Appeals for the District of Columbia Circuit voted 2-1 to temporarily block Trump’s Republican administration from firing Shira Perlmutter as the register of copyrights, who advises Congress on copyright issues.

Perlmutter claims Trump fired her in May because he disapproved of advice she gave to Congress in a report related to artificial intelligence. Perlmutter had received an email from the White House notifying her that “your position as the Register of Copyrights and Director at the U.S. Copyright Office is terminated effective immediately,” her office said.

Circuit Judges Florence Pan and J. Michelle Childs concluded that Perlmutter’s purported firing was likely illegal.

“The Executive’s alleged blatant interference with the work of a Legislative Branch official, as she performs statutorily authorized duties to advise Congress, strikes us as a violation of the separation of powers that is significantly different in kind and in degree from the cases that have come before,” Pan wrote in the majority opinion.

The White House had no immediate comment on the court’s decision.

Perlmutter’s position is considered part of the legislative branch of government. Her office is housed within the Library of Congress. Its director is chosen by the librarian of Congress, who is also a legislative branch employee but is nominated by the president and is subject to Senate confirmation.

U.S. District Judge Timothy Kelly, a Trump nominee, ruled in May that Perlmutter failed to meet her legal burden to show how removing her from the position would cause her irreparable harm.

Pan and Childs, who were nominated by President Joe Biden, a Democrat, concluded that Kelly abused his discretion and failed to weigh other factors favoring Perlmutter’s request for a preliminary injunction.

“The President’s purported removal of the Legislative Branch’s chief advisor on copyright matters, based on the advice that she provided to Congress, is akin to the President trying to fire a federal judge’s law clerk,” Pan wrote.

Judge Justin Walker, a Trump nominee, wrote a dissenting opinion in which he said the register of copyrights “exercises executive power in a host of ways.”

“Recently, repeatedly, and unequivocally, the Supreme Court has stayed lower-court injunctions that barred the President from removing officers exercising executive power,” Walker wrote.

Pan said it appears Perlmutter is still serving as register despite her purported removal.

“And because she continues to serve as Register at the present time, ruling in her favor would not disrupt the work of the U.S. Copyright Office,” Pan wrote. “To the contrary, it is her removal that would be disruptive.”

Perlmutter’s attorneys say she is a renowned copyright expert who also has served as register of copyrights since then-Librarian of Congress Carla Hayden appointed her to the job in October 2020.

Trump appointed Deputy Attorney General Todd Blanche to replace Hayden at the Library of Congress. The White House fired Hayden amid criticism from conservatives that she was advancing a “woke” agenda.

The appeals court’s ruling says Blanche’s appointment to serve as acting librarian of Congress was likely unlawful, as well, because the position is subject to Senate confirmation.