More than a dozen prominent conservative groups and Catholic institutions are asking Capitol Hill leaders to overturn a pair of laws passed last year by the D.C. Council, calling them “unprecedented assaults upon our organizations,” setting the stage for a possible new intervention in the Democratic-majority city’s affairs from the Republican-majority Congress.

The laws being targeted would restrict the ability of private groups to discriminate based on religious beliefs. One bill, the Reproductive Health Non-Discrimination Amendment Act of 2014, would prevent employers from taking action against workers based on their decision to use birth control or seek an abortion. Another bill, the Human Rights Amendment Act of 2014, repeals a longstanding, congressionally imposed measure exempting religious educational institutions from the city’s gay nondiscrimination law.

“Most of us do not engage in the city’s legislative affairs, but we must do so now with one voice against two recently enacted laws that are unprecedented assaults upon our organizations,” reads the letter addressed to House members Thursday. “Both laws violate the freedom of religion, freedom of speech, and freedom of association protected by the First Amendment and other federal law.”

The signers include leaders of Heritage Action for America, the Family Research Council and the National Organization for Marriage, as well as representatives from the Catholic University of America, the Archdiocese of Washington and the U.S. Conference of Catholic Bishops.

Both bills have come under sharp criticism from conservative commentators, particularly the human rights bill, which would repeal the 1989 “Armstrong Amendment” passed in response to a lawsuit filed under the D.C. Human Rights Act to force Georgetown University to recognize a gay student organization. Georgetown, notably, is not among the signers of the new letter.

According to council records, the bills have been signed by Mayor Muriel E. Bowser (D) but have yet to be transmitted to Congress for the requisite 30-legislative-day review period. Overturning a D.C. law requires a joint resolution passed by both houses of Congress and a presidential signature; the maneuver is rare and has not succeeded since the early 1990s. But Republican leaders on Capitol Hill could see bringing a disapproval resolution to the House and Senate floors as a straightforward way to signal their respect for these influential conservative organizations.

And, still, the potential intervention has District leaders wary. Last week, after Heritage Action declared its intention to overturn the bills, Eleanor Holmes Norton (D), the District’s nonvoting House delegate, issued a statement decrying the group as “anti-democrats,” small-D: “Just as my colleagues insist that the laws of their constituents be respected by Washington, you better bet that we will insist on the same American principle and will target members who dare disrespect the people of the District of Columbia by trying to overturn our local laws.”

Benjamin Fritsch, a spokesman for Norton, said in light of the new letter, her prior sentiment stands. He added, “A disapproval resolution is particularly premature when the District has sent no bill to Congress.”

In another sign that city leaders are wary of intervention, the Bowser administration last week sent the council an emergency bill that would make clear that the Reproductive Health Non-Discrimination Amendment Act would not force employers to provide coverage for contraception and abortions for their workers. That fix, which could get a vote later this month, earned a mention in the letter, which said the new bill would still “fail to resolve” the groups’ concerns.

Michael Czin, a spokesman for Bowser, urged “everyone, regardless of political leanings, to respect the democratic process of District residents.”