A significant fight is brewing in Congress over a defense funding bill and whether it should include language that would enable religiously affiliated contractors doing business with the federal government to discriminate based on sexual orientation and gender identity.

“We see this, in fact, as one of the most significant threats to LGBT people and to women that Congress has put forward in years,” said ACLU Deputy Legal Director Louise Melling.

The language appears in a House version of the National Defense Authorization Act (NDAA) for FY 2017 passed in May. The Senate passed its version, too, which does not include the language. A House-Senate conference committee tried to hammer out a final version of the bill to send back to both chambers but failed to do so before it recessed in September.

The language in the House version of the bill is known as Section 1094 or “the Russell Amendment” –named after its sponsor, Rep. Steve Russell of Oklahoma.

Opponents say the Russell Amendment would provide sweeping exemptions to federal civil rights laws for a wide variety of religiously affiliated institutions. And, according to Senator Richard Blumenthal (D-Conn.), who is leading the fight against the amendment, the language would allow discrimination against women, LGBT people, and people of various religions in “every federal department,” not just the Department of Defense.

Blumenthal and 41 other senators signed an October 25 letter opposing the amendment. They include 40 Democrats, 2 independents, and no Republicans. The four Democrats not signed onto the letter are Senate Minority Leader Harry Reid of Nevada and Senators Joe Donnelly of Indiana, Joe Manchin of West Virginia, and Jack Reed of Rhode Island.

The letter states: “If enacted, Section 1094 would vastly expand religious exemptions under the Civil Rights Act and the Americans with Disabilities Act to allow religiously-affiliated organizations receiving federal funds to engage in discriminatory hiring practices –using taxpayer dollars to harm hardworking Americans who deserve to be protected from workplace discrimination based on sexual orientation, gender identity, religious identity, or reproductive and other healthcare decisions.”

The letter says Section 1094 would also undermine protections for LGBT people under President Obama’s Executive Order 13672, prohibiting sexual orientation and gender identity discrimination by federal contractors. In May, the Obama administration released a statement detailing a number of its objections to the bill, including that it “would make it easier to discriminate on the basis of sexual orientation.”

The overall NDAA is an annual bill that stipulates how the Defense Department can spend its federal funding. The House version is HR 4909; the Senate version is S. 2943. This year’s bills include a number of controversial measures, including language to require women to register for any potential draft into the military. A House-Senate conference committee was unable to come up with a final version of the NDAA before Congress adjourned in September. It will have to take the task up again when Congress reconvenes following the November 8 election.

Only the House version of the bill includes the amendment that would seek to allow religious entities to discriminate against LGBT, women, and people of faith. During House consideration of the NDAA in May, openly gay U.S. Rep. Sean Patrick Maloney (D-NY) led an attempt to preserve President Obama’s LGBT executive order. Maloney’s amendment had sufficient support, but the Republican chair of the House allowed voting beyond the allotted time until enough Republicans could be convinced to change their votes and the Maloney amendment failed. House Speaker Paul Ryan later allowed the House to entertain the Maloney amendment again and it passed, but then the overall bill failed.

The text of the anti-LGBT amendment introduced by Russell sounds innocent enough: It states that the federal government will provide “protections and exemptions” for religious institutions “consistent with” certain sections of the Civil Rights Act and the Americans with Disabilities Act. Of the Civil Rights Act, the amendment identifies Section 702(a), which says the act does not apply to religious institutions, and Section 703(e)(2), which says the act does not apply to any religiously affiliated educational institution. Of the Americans with Disabilities Act, the amendment identifies Section 103(d), which says religious institutions can give preference to employees of a particular religion.

But opponents say the language would create a vast loophole for religious schools, hospitals, charities, and other institutions, large and small, to discriminate against employees who don’t comply with the institutions’ religious beliefs.

In a telephone press conference October 25, Senator Blumenthal said opponents of the bill hope to eliminate the language from the bill before the final version reaches the House and Senate floors again for approval.