A federal judge in Washington D.C. has issued a preliminary injunction against the Trump administration over its attempt to ban transgender troops from serving in the U.S. military.

Tuesday’s decision by U.S. District Judge Ana C. Reyes blocks the Department of Defense from carrying through with a policy directive designed to remove transgender service members from the military.

In a sweeping and at times strongly worded opinion, Reyes pushed back against the administration effort, writing that the ban violated the constitutional rights of transgender troops.

“Indeed, the cruel irony is that thousands of transgender servicemembers have sacrificed — some risking their lives – to ensure for others the very equal protection rights the Military Ban seeks to deny them,” Reyes wrote.

The preliminary injunction is the latest example of a federal court moving to pause or block efforts by President Trump to enact his agenda through executive action. The steady cascade of orders against the president has raised fears among Trump critics that the administration may in time choose to defy a federal court decision and spark a potential constitutional crisis.

Trump has pledged to adhere to court decisions, saying he would appeal rulings where judges have sided against the administration. At the same time, he has been openly critical of federal judges who have ruled against him.

There are about 1.3 million military service personnel. The Defense Department has told NPR that an estimated 4,240 active duty service members have gender dysphoria — or less than 1% of forces. But others have put the number higher. Palm Center, a research institute that advocates for LGBTQ+ inclusion within the U.S. military, estimated in 2018 that the number of transgender troops was about 14,700.

The challenge was brought by six transgender service members and two prospective service members in response to a Jan. 27 executive order that sought to bar transgender troops from serving in the military and directed the Pentagon to release a plan for carrying it out within 30 days. 

The executive order described transgender identity as harmful to military readiness, writing that “the Armed Forces have been afflicted with radical gender ideology to appease activists unconcerned with the requirements of military service like physical and mental health, selflessness, and unit cohesion.”

It’s language that Reyes took issue with in her decision. 

“The President has the power—indeed the obligation—to ensure military readiness,” she wrote. “At times, however, leaders have used concern for military readiness to deny marginalized persons the privilege of serving.”

In February, the Pentagon moved to begin implementing the order with a policy memo describing service members or applicants for military service who have “a current diagnosis or history of, or exhibit symptoms consistent with, gender dysphoria” as “incompatible” with U.S. military service.

The policy directive called for new procedures to identify service members with gender dysphoria or a history of it and to “begin separation actions.”