Attorney General Jeff Sessions. AP Photo/Brynn Anderson, file

The Department of Justice has argued that a pivotal civil-rights law does not protect a worker's sexual orientation against discrimination, according to a new legal brief published Wednesday.

Pitted against the Equal Employment Opportunity Commission, a federal agency that oversees discrimination complaints in the workplace, the DOJ argued in its amicus brief that the US Court of Appeals for the Second Circuit should reaffirm a previous ruling that the protection of Title VII "does not reach discrimination based on sexual orientation."

Title VII of the Civil Rights Act prohibits employers from discriminating against their employees on the basis of race, color, religion, sex, and national origin.

The case the DOJ weighed in on with the brief involves Donald Zarda, a skydiving instructor who alleged in a 2010 lawsuit that a former employer, Altitude Express, had violated Title VII by firing him for being gay.

"Following one jump, a customer complained that Zarda had disclosed his homosexuality and other personal details during the jump," a legal brief from the EEOC said. "Zarda was fired soon thereafter."

The US District Court for the Eastern District of New York first rejected Zarda's claim by ruling that Title VII does not offer protection on the basis of sexual orientation.

Zarda died in a base-jumping accident in 2014, though representatives of his estate have continued the lawsuit.

"The sole question here is whether, as a matter of law, Title VII reaches sexual orientation discrimination," the Justice Department's brief said. "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."

It continued: "Although the Equal Employment Opportunity Commission (EEOC) enforces Title VII against private employers ... the EEOC is not speaking for the United States and its position about the scope of Title VII is entitled to no deference beyond its power to persuade."

The new filing came the same day President Donald Trump made a surprise announcement that transgender people would be barred from serving in the military.