The federal Government Accountability Office issued a blow to D.C. today, issuing an opinion that the city’s budget autonomy referendum has no legal standing.

The referendum, which District voters overwhelmingly approved last April, would amend the Home Rule Charter to allow the D.C. government to spend its own tax revenue without approval from Congress. The law was set to go in effect on Jan. 1, but since, in the wake of the government shutdown, Congress passed legislation that would allow the District to spend its own money without congressional approval through September 2015, the law wouldn’t be tested until after that date.

If it is tested, the GAO believes, it might be in some trouble.

“[The] District Government acted beyond the scope of its authority when it attempted to enact the Budget Autonomy Act,” Susan A. Poling, the general counsel of the GAO, wrote in the report examining the constitutionality of the Local Budget Autonomy Amendment Act of 2012.

She says the budget referendum has “no legal effect” and spending money without congressional approval would violate the Antideficiency Act.

The report was issued at the request of the House Subcommittee on Financial Services and General Government, a subcommittee within the House Committee on Appropriations that sets the District budget.

Although the report is not legally binding, it will presumably carry weight as Congress and District officials determine how and if to implement the budget autonomy act.

“While we are disappointed, we are not surprised by the GAO’s legal opinion as it mirrors the opinion that the District’s own Attorney General rendered to the Board of Elections,” Mayor Vince Gray said in a statement. “While we will continue working to secure both budget and legislative autonomy for the District, we intend to comply with all valid federal and local laws.”

D.C. Attorney General Irv Nathan, who had warned that the referendum wouldn’t bind Congress, issued a statement saying federal lawmakers should act to moot the referendum and the report. “We are gratified that the GAO has recognized that our legal assessment was correct,” Nathan said. “We continue to regret that the citizens were led in the referendum to believe that their votes would alter the federally prescribed budget process, but believe the Congress should give effect to the strongly voiced opinion of our citizens that budget autonomy is fair and just and should be accorded to the District.”

Read the full report here.

Photo by Darrow Montgomery.