Hours after President Trump signed a darkly worded executive order targeting transgender service members, rights groups filed a lawsuit on Tuesday saying that the ban violates the Constitution.

The order framed transgender service members in harsh terms, saying the military had been “afflicted with radical gender ideology” that had crippled its effectiveness.

The statement does not use the word “transgender” but appears to call for a ban on transgender people serving, saying that “adoption of a gender identity inconsistent with an individual’s sex conflicts with a soldier’s commitment to an honorable, truthful and disciplined lifestyle, even in one’s personal life.”

The order authorizes the Defense Department to make rules that would effectively bar transgender troops by considering identifying as a gender other than the one assigned at birth as disqualifying for military service.

“It really is the nuclear option, it is really as sweeping as can be,” said Shannon Minter, the legal director of the National Center for Lesbian Rights. “The only impact this will have is to exclude service members who are otherwise qualified and meeting the same standards as everyone else.”

The center, along with the GLBTQ Legal Advocates and Defenders, filed the suit challenging the ban on behalf of six active service members and two individuals who are seeking to enlist.