A Republican on the House Appropriations Committee is reportedly introducing an amendment to the District’s appropriations bill that would block the city from implementing its recently adopted marijuana decriminalization law.

A spokeswoman for the committee says she can’t confirm that an amendment will be introduced, but Maryland Rep. Andy Harris, a medical doctor, confirmed to a Roll Call reporter that he would be introducing it.

Mayor Vince Gray signed off on the local legislation that would decriminalize possession of up to an ounce of marijuana in the city in March. Like all other bills passed in D.C., the decriminalization bill is subject to 60 days of review by Congress. But after a House hearing and some threats to quash the law, it actually looks like that bill will survive the review period.

The amendment expected to be introduced tomorrow would technically not kill the law—but it would prevent the city from spending any money enacting it. (In case you’ve forgotten: Congress technically controls the District’s entire budget, even locally raised revenue.)

“Considering the recent House hearing on the city’s decriminalization bill, but on none of the states that have decriminalized marijuana, we certainly are not surprised, and we have been preparing for Republicans to try to block D.C.’s marijuana decriminalization bill,” Rep. Eleanor Holmes Norton said in a release warning about the possibility of the amendment. “I had hoped that D.C. was in good company with the 17 states that had decriminalized marijuana before the city did.”

Last week, Roll Call reported that it looked like the decriminalization bill would make it through the appropriations process without a rider to block it after the House Financial Services and General Government Appropriations Subcommittee introduce a slate of social policy-related riders, but not one for the decriminalization bill. Even Norton told Roll Call “we have too many allies now” for anyone to try to block the  legislation.

Even if the amendment passes the appropriations committee, it would still have to pass the entire House and Democratic-controlled Senate—and be signed by President Barack Obama—to take effect.

“As expected, Republicans are using a rider rather than the disapproval process set forth in the Home Rule Act to block D.C.’s decriminalization bill,” Norton’s release says.

Harris’ office did not immediately return a request for comment.

Illustration by Carey Jordan