The American Civil Liberties Union (ACLU) and the Human Rights Campaign (HRC) are among the groups who have condemned the Department of Justice's position that LGBT people are not protected from workplace discrimination under federal law.

On Wednesday, the Justice Department, which is led by Attorney General Jeff Sessions, filed a friend-of-the-court brief in a case before the Second Circuit Court of Appeal in which it argued that Title VII of the Civil Rights Act of 1964 does not prohibit workplace discrimination based on sexual orientation.

Plaintiff in the case is the estate of Donald Zarda, which claims that his employer, Altitude Express, fired him because he's gay. A three-judge panel in April ruled against Zarda, saying that Title VII does not apply to sexual orientation. Lawyers in the case appealed to the full court.

Under former Attorney General Eric Holder, the department held that Title VII protected against discrimination on the basis of gender identity. The Justice Department, however, has not previously held that Title VII protects on the basis of sexual orientation.

Several courts, most recently the Seventh Circuit Court of Appeals in Chicago, have held that Title VII's prohibition on sex discrimination applies to discrimination based on a person's sexuality.

The DOJ filed the brief on the same day that President Donald Trump announced in a series of tweets that the military will no longer “accept or allow” transgender troops.

(Related: Trump says military will bar transgender troops.)

“On the day that will go down in history as Anti-LGBT Day, comes one more gratuitous and extraordinary attack on LGBT people’s civil rights,” said James Esseks, director of the ACLU's LGBT & HIV Project. “The Sessions-led Justice Department and the Trump administration are actively working to expose people to discrimination.”

“Fortunately, courts will decide whether the Civil Rights Act protects LGBT people, not an Attorney General and a White House that are hell-bent on playing politics with people's lives. We are confident that the courts will side with equality and the people,” he added.

HRC Legal Director Sarah Warbelow described the filing as a “shameful retrenchment of an outmoded interpretation that forfeits faithful interpretation of current law to achieve a politically-driven and legally specious result.”