(Reuters) -The U.S. Department of Labor has reinstated about 120 employees who were facing termination as part of the Trump administration's mass firings of recently hired workers, a union said on Friday.

The American Federation of Government Employees, the largest federal employee union, said the probationary employees had been reinstated immediately and the department was issuing letters telling them to report back to duty on Monday.

"It's our understanding that this decision affects about 120 employees, most of whom had been placed on administrative leave," Tim Kauffman, a union spokesperson, said in a statement.

A letter to one employee reviewed by Reuters advised the department would "use the remainder of your probationary/trial period to determine if your appointment is in the best interest of the public."

The Labor Department did not respond to a request for comment.

The Labor Department employees were reinstated a day after U.S. President Donald Trump told his cabinet members that they, not Elon Musk, had the final say on staffing and policy at their agencies.

Musk and his team at the Department of Government Efficiency have been tasked by Trump to slash the size and cost of the federal bureaucracy. To date about 25,000 workers have been fired, and another 75,000 have taken a buyout, out of the 2.3 million federal civilian workforce.

Trump on Thursday, though, said while it was "very important that we cut levels down to where they should be," agencies should use a "scalpel" rather than a "hatchet" for job reductions.