The U.S. Supreme Court decided on Tuesday to deny an emergency challenge to New York City’s COVID-19 vaccine mandate for municipal employees.

The case centers around NYPD Detective Anthony Marciano, whose legal team requested in late August that the nation’s highest court intervene on his behalf and that of any other city employee who has refused the requirement. This mandate is nearly a year old and was issued during the final months of the de Blasio administration.

Marciano’s challenge claims the mandate was illegal given that the requirement was issued before the COVID-19 vaccines were given full approval from the federal government. His claim has been stalled in the U.S. 2nd Circuit of Appeals since midsummer.

Marciano’s initial petition to the Supreme Court stated he would be put on paid leave by Sept. 7 and potentially terminated without the emergency injunction. Justice Sonia Sotomayor, a Bronx native, individually denied the application, meaning the case wouldn’t be considered by the court. But less than a month later, Marciano’s lawyer refiled with Justice Clarence Thomas, who opted to move the request before the full court. That hearing happened last Friday.

Attorney Patricia Finn, who is representing Marciano in the case, said via email on Tuesday that she assumed the Supreme Court denied the injunction due to a similar lawsuit that is now moving through New York courts.

The Police Benevolent Association, a union representing rank-and-file officers, won a temporary motion two weeks ago from a state Supreme Court that reinstated members who had been fired or put on leave for refusing the vaccine mandate. A full decision on that case is still pending.

“This is after all a state court issue and belonged in state court,” said Finn, who isn’t representing the PBA case. But she said she hopes Marciano’s case would still prevail in federal appeals court.

Finn said Marciano is not on leave and is currently working for the NYPD. The New York City Law Department did not respond to a request for comment.

Correction: A previous version of this story misstated the day of the Supreme Court decision.