House Republicans issued a report Tuesday making clear that they do not believe the District’s budget autonomy referendum is legal, the clearest sign yet that the measure has an uncertain fate.

By a wide margin in an April referendum, city voters approved letting the city spend locally raised funds without congressional approval and to continue D.C. government operations in a federal shutdown. The measure also lets the District set its own fiscal calendar.

The referendum has been the subject of legal debate, with some critics — including D.C. Attorney General Irvin B. Nathan — contending that it could be unconstitutional and subject to legal challenges. Congress has taken no official action to sue or overturn the law legislatively.

But with a spending bill covering funds for the District set for a panel vote Wednesday, the House Appropriations Committee has issued a report accompanying the legislation that takes a firm stand on the autonomy measure.

“The Committee considers the recent referendum in the District as an expression of the opinion of the residents, only, and without any authority to change or alter the existing relationship between Federal appropriations and the District,” the report says.

The report represents the views of Republican members of the committee, and the language has the backing of House Speaker John A. Boehner (R-Ohio).

“The House is simply expressing agreement with the District of Columbia’s mayor and attorney general that a referendum is not a legal or appropriate means of changing rules regarding the District’s budget,” said Michael Steel, a spokesman for Boehner.

Because of Nathan’s concerns, Mayor Vincent C. Gray (D) initially urged the D.C. Council not to put the referendum on the ballot, because “the cause of getting Congress to approve D.C. budget autonomy may be set back many years if Members bristle at this attempt to circumvent their authority.”

But Gray changed his tune and urged District voters to approve the measure. He reiterated his support in a statement Wednesday.

“Residents are understandably frustrated that the District’s budget continues to be ensnared in partisan federal budget battles,” Gray said. “The language in the committee report does not, and will not, bar us from working with the Committee and leaders on the Hill to ensure that budget autonomy is implemented as quickly as possible.”

The House report does not have any legal impact on the measure, and the Democratic-controlled Senate will write its own D.C. spending bill that likely won’t include the same language. The House could move to pass separate legislation overturning the referendum, or House leaders could decide to challenge it on constitutional grounds.

Daniel van Hoogstraten, a spokesman for Del. Eleanor Holmes Norton (D-D.C.), put a positive spin on the language.

The Appropriations Committee “took no action to block the budget autonomy referendum,” van Hoogstraten said. “We are grateful that the referendum remains unchallenged but we are continuing to make every effort to preserve the overwhelming will of District residents, expressed through the democratic process, to spend their local funds they alone raise.”

House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.) has been trying to move separate legislation that would grant some budget autonomy to the District, but he has been stymied by lawmakers seeking to tack on language changing the city’s laws on guns, abortion and other issues.