A federal judge in San Francisco has ordered the National Park Service and five other federal agencies to immediately reinstate probationary employees who were fired en masse last month, ruling that the Office of Personnel Management had no legal authority to mandate their terminations.

U.S. District Judge William Alsup, in a scathing rebuke of the Donald Trump administration’s actions, declared the mass firings a violation of federal law and accused officials of using procedural loopholes to sidestep legal protections. In addition to 1,000 employees who were terminated from the park service, his order affects employees at the departments of Veterans Affairs, Agriculture, Defense, Energy, the Interior and the Treasury, who were abruptly dismissed in February.

“It is a sad, sad day when our government would fire some good employee and say it was based on performance when they know good and well that’s a lie,” Alsup said from the bench. “That should not have been done in our country. It was a sham in order to avoid statutory requirements.”