The US Justice Department on Wednesday argued in a major federal lawsuit that a 1964 civil rights law doesn’t protect gay workers from discrimination, thereby diverging from a separate, autonomous federal agency that had supported the gay plaintiff’s case.

The Trump administration’s filing is unusual in part because the Justice Department isn’t a party in the case, and the department doesn’t typically weigh in on private employment lawsuits.

But in an amicus brief filed at the US Court of Appeals for the Second Circuit, lawyers under Attorney General Jeff Sessions contend that Title VII of the Civil Rights Act of 1964, which bans sex discrimination, does not cover sexual orientation.

"The sole question here is whether, as a matter of law, Title VII reaches sexual orientation discrimination," says the Justice Department's brief. "It does not, as has been settled for decades. Any efforts to amend Title VII’s scope should be directed to Congress rather than the courts."

The Justice Department also contends that Title VII only applies if men and women are treated unequally.

The scope of Title VII has been disputed for years.

Under Obama, the government argued Title VII's ban on sex discrimination also included gender identity — thereby barring discrimination against transgender workers. But the Obama administration never went as far to say the civil rights law also covered sexual orientation. It had in fact opposed the argument, claiming that its hands were tied by prior court precedent. Yet in 2016, the Obama administration arguably dialed back its opposition by not trying to dismiss a case brought on those grounds.

If Zarda’s argument were to prevail — despite his death in base-jumping accident in 2014 — it would set new precedent in the circuit by overturning two cases from the 2000s.

Further, it would give momentum to the argument as a general matter, given that the 7th Circuit ruled in favor of lesbian in April who made the same claim. Read more via Buzzfeed