For more than a year, a federal ethics agency has instructed federal employees to steer clear of taking a stand at work for or against the impeachment of President Donald Trump , saying that doing so could run afoul of the Hatch Act that bars them from participating in certain political activities.

With Trump now impeached and the subject of a Senate trial, a union representing federal employees says that the controversial legal guidance from the Office of Special Counsel (OSC) tramples on workers First Amendment rights.

As part of a lawsuit that began last year, the American Federation of Government Employees (AFGE) filed an emergency motion in federal court last Friday asking a judge to block the guidance with an injunction. The union argues that the OSC, an independent agency now headed by a Trump appointee, has misread the Hatch Act in a way thats created a chilling effect among federal employees.