The administration’s newest emergency appeal to the high court was filed a month and a half after a federal appeals court in Washington held that the official, Shira Perlmutter, could not be unilaterally fired.

Nearly four weeks ago, the full U.S. Court of Appeals for the District of Columbia Circuit refused to reconsider that ruling.

The case is the latest that relates to Trump’s authority to install his own people at the head of federal agencies. The Supreme Court has largely allowed Trump to fire officials, even as court challenges proceed.

A divided appellate panel ruled that Perlmutter could keep her job while the case moves forward.

“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,” Judge Florence Pan wrote for the appeals court. Judge Michelle Childs joined the opinion. Democratic President Joe Biden appointed both judges to the appeals court.

Judge Justin Walker, a Trump appointee, wrote in dissent that Perlmutter “exercises executive power in a host of ways.”

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.