A federal judge in San Francisco on Thursday found that the mass firings of probationary employees were likely unlawful, granting some temporary relief to a coalition of labor unions and organizations that has sued to stop the Trump administration’s massive trimming of the federal workforce.

A California federal judge said that the U.S. Office of Personnel Management lacked the power to order federal agencies to fire any workers, including probationary employees who typically have less than a year of experience.

Federal employees are finding openings to overturn Trump administration terminations after a judge questioned the legality of the government’s firing memos and an independent board ordered some agencies to temporarily reinstate several workers.