Donald Trump’s Justice Department has filed a legal brief arguing against legal protections against discrimination based on sexual orientation.

The move, in court papers filed in the United States Court of Appeals for the Second Circuit today, confirms a U-turn from the Obama administration, which had often used amicus briefs to intervene in court cases in favour of LGBT rights protections.

The Justice Department intervened in a discrimination case, to argue that civil rights laws should not protect gay workers from discrimination.

The department, led by Attorney General Jeff Sessions, argued that the 1964 Civil Rights Act – which outlaws discrimination based on a number of characteristics – does not provide any protections for gay people, despite outlawing sex-based discrimination.

If the administration’s view is upheld by the courts, it could have a chilling effect – effectively declaring open season for discrimination across the country.

Sarah Warbelow, HRC Legal Director, told PinkNews in a statement: “Attacks against the LGBTQ community at all levels of government continue to pour in from the Trump-Pence Administration.

“In one fell swoop, Trump’s DOJ has provided a roadmap for dismantling years of federal protections and declared that lesbian, gay, and bisexual people may no longer be protected by landmark civil rights laws such as the Fair Housing Act, Title IX, or Title VII.

“For over a decade, courts have determined that discrimination on the basis of LGBTQ status is unlawful discrimination under federal law.

“Today’s filing is a shameful retrenchment of an outmoded interpretation that forfeits faithful interpretation of current law to achieve a politically-driven and legally specious result.”

The case surrounds skydiving instructor Donald Zarda, who was allegedly fired by his employer Altitude Express for being gay.

Zarda’s case had been backed by the Equal Employment Opportunity Commission. but the Justice Department weighed in on the opposite side.

The Trump administration contends that “the essential element of sex discrimination under [civil rights law] Title VII is that employees of one sex must be treated worse than similarly situated employees of the other sex, and sexual orientation discrimination simply does not have that effect”.

It adds: “Congress has made clear through its actions and inactions in this area that Title VII’s prohibition of sex discrimination does not encompass sexual orientation discrimination”.

The administration directs: “This Court should reaffirm its precedent holding that Title VII does not prohibit discrimination because of sexual orientation.”

The decision comes the same day that Trump sparked anger by announcing a ban on transgender people serving in the US military.

In a string of Twitter posts, the President claimed that the military “cannot be burdened with the tremendous medical costs and disruption that transgender would entail”.