A federal judge has issued a preliminary injunction blocking a move by the Trump administration to transfer three transgender women to all-male prisons, agreeing the inmates would be at a “substantially elevated risk” of physical and sexual violence and the move would exacerbate their mental health conditions.

U.S. District Judge Royce Lamberth, a Ronald Reagan appointee, issued the preliminary injunction on Tuesday in a federal lawsuit involving the inmate plaintiffs.

Lamberth said that withholding the inmates’ prescribed hormone therapy medication would likely cause severe harm.

“Importantly, the defendants did not substantially dispute those facts,” he wrote. “Instead, the defendants pointed to speculative action that the Bureau of Prisons might take to mitigate those harms and thus assuage the Court’s Eighth Amendment concerns. Those hypothetical measures were insufficient to defeat the plaintiffs’ largely uncontroverted evidence of harm.”

He added that since a temporary restraining order was issued in the case, the Court received no further information about what steps, if any, the government intends or would take if the plaintiffs were to be transferred and deprived of their prescribed medications.