The nation’s largest union of federal workers filed suit against the Trump administration on Wednesday over an executive order signed by President Donald Trump that seeks to deny workers the right to job site representation—an established guarantee in existing labor law.

“This is more than union busting – it’s democracy busting.” —J. David Cox Sr., AFGE president

The lawsuit (pdf) by the American Federation of Government Employees (AFGE), a member of the AFL-CIO which represents approximately 700,000 federal employees, argues that among a slate of anti-worker orders signed by the president last Friday, one of them specifically exceeds the president’s constitutional authority and violates the First Amendment right of workers to freely associate.

“This president seems to think he is above the law, and we are not going to stand by while he tries to shred workers’ rights,” said  AFGE national president J. David Cox Sr., in a statement announcing the lawsuit. “This is a democracy, not a dictatorship. No president should be able to undo a law he doesn’t like through administrative fiat.”

As the Cleveland Plain Dealer reported on Friday, the executive orders signed by Trump last week are “intended to crack down on unions that represent federal employees and to make it easier to fire federal workers.”