The firings of over 5,000 probationary employees at the Agriculture Department may have been unlawful, and the workers should be reinstated for at least the next 45 days, a federal civil service board ruled Wednesday.

The decision is a blow to the Trump administration’s effort to drastically and quickly shrink the federal bureaucracy.

A workers’ board is reinstating – at least temporarily – almost 6,000 fired probationary workers from the Department of Agriculture, according to a newly issued order obtained by CNN.