There is no sign that Congress plans to overturn or challenge the District’s budget autonomy referendum that passed last month, but D.C. leaders vowed Tuesday to be on guard against any effort to do so.

Mayor Vincent Gray (D) joined Del. Eleanor Holmes Norton (D-D.C.) and local activists on Capitol Hill for a news conference to warn against the addition of “riders” on issues such as abortion, gun laws and needle exchange programs to the forthcoming appropriations bill covering the District. And they said they would keep an eye out on the budget autonomy front.

“As far as we’re concerned, no news is good news,” Norton said, adding later that “we’ve heard of no plans” afoot to overturn the referendum.

District residents voted April 23 by an overwhelming margin to approve a measure allowing the city to spend locally-raised money without waiting for approval from Congress. The referendum also allows D.C. to set its own fiscal year calendar and to keep services running in the event of a federal government shutdown.

Critics of the measure and some legal experts have called it unconstitutional. It could be challenged in court or overturned by Congress, which has 35 legislative days after receiving the measure to approve a joint resolution doing so before it takes effect.

But while that 35-day period will end this summer, Norton noted that Congress could decide to repeal the law after that simply by attaching language to unrelated legislation. “Congress can move at any point,” she said.

Norton said that she “had a very long meeting” last week with House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.), and that he “remains very committed to helping us” achieve autonomy.

Issa has pushed to pass legislation granting autonomy to the District, though he has faced resistance from some lawmakers who want to attach provisions related to the city’s abortion and gun laws. Issa’s office did not respond to a request for comment Tuesday on the status of his effort.

Meanwhile, the House Appropriations Committee has not scheduled a markup of its annual bill covering the District budget.

Republicans have consistently succeeded in inserting language prohibiting the city from spending its own money to provide abortions to low-income women, but otherwise the number of riders attached to the D.C. spending bill has gone down.

“The fact that we are seeing some reduction in the number of riders that have been imposed in the first place suggests that people are recognizing … that this is a well-run city, that we are a growing city, and that frankly, some of these things look ridiculous,” Gray said Tuesday.

Separate from the appropriations process, Rep. Chris Smith (R-N.J.) and Sen. Roger Wicker (R-Miss.) have offered bills to make permanent the ban on the District spending its own money to provide abortions. And Rep. Trent Franks (R-Ariz.) and Sen. Mike Lee (R-Utah) have each introduced bills that would ban abortions in the District after 20 weeks of pregnancy. Franks has said he will amend his bill to apply nationwide; Lee has not decided yet whether to do the same.