Federal layoffs are starting with huge numbers of probationary workers, and there are warnings of bigger cuts on the way.

As the Trump administration carries out mass firings of the federal workforce in a push to slash government spending, its targeting probationary workers. Here's what to know about the employee status.

The dismissal of probationary employees is expected to be the first step in sweeping layoffs. Trump signed an executive order telling agency leaders to plan for “large-scale reductions in force.”