The District’s attorney general implored elections officials Monday to halt a voter referendum that would give local leaders more freedom to spend funds without congressional approval, testifying that the measure plainly exceeds the city’s powers.

Irvin B. Nathan told the three-member Board of Elections it was a “difficult and sad” task to counsel against the budget autonomy referendum, whose policy goals he supports. But he said it “may well be in the long-term best interest of the District” to avoid litigation and the political ramifications that could ensue should voters approve the measure during an April 23 special election.

Those effects, Nathan said, could include “punitive measures” from Congress. “To put it mildly, it is not likely to be pretty,” he said.

He quoted a newspaper interview in which Rep. Darrell Issa (R-Calif.), chairman of a key House committee, referred to the referendum as a “partial secession.”

But D.C. Council Chairman Phil Mendelson (D), also testifying before the board, said he was “shocked” by Nathan’s position and what he called a “Johnny-come-lately” decision to register his concerns with the elections board. The council unanimously authorized the referendum last month.

Monday’s hearing was meant to help formulate ballot language for the referendum, which would amend the District charter to allow the city to spend locally raised tax dollars without congressional appropriation. The attorney general’s office has expressed objections to the referendum strategy in an internal memorandum. However, neither Nathan nor his deputies registered objections with the council. Mayor Vincent C. Gray (D) sent Mendelson a letter expressing strong reservations, echoing the memo’s concerns, but ultimately signed the bill.

The board adjourned without making a decision on the referendum; board attorney Kenneth J. McGhie said a ruling is expected Tuesday morning.

V. David Zvenyach, the council’s chief attorney, argued at the hearing that the board simply has no legal power to review charter-amending measures passed by lawmakers.

“The board may have doubts,” he acknowledged. “But it’s not the role of the board . . . or of the attorney general, frankly, to say that what the considered judgment of the elected officials is should not go forward.”

Nathan, in turn, pointed to a 1972 federal court decision holding that government agencies performing merely perfunctory roles are obligated to observe relevant laws.

The board’s chairwoman, Deborah K. Nichols, noted the city charter established separate processes for ballot measures initiated by voters, for which the board has a well-defined legal review role, and for council-initiated charter amendments, for which it does not.

“What legal authority is there for us to step in?” she asked Nathan, adding that the 1972 case had only “vague” application to the situation.

Another board member, Stephen I. Danzansky, appeared more confident the board could intervene. He raised a hypothetical situation where the council voted to abolish the mayoralty.

“Is [the board] a potted plant, in a sense?” he asked. “Or can it say, ‘Wait a minute, time out, this is a clear violation of the charter, and we are not going to pass this on?’ ”

Zvenyach argued the board’s role is, in fact, essentially vegetative: “Even ill-considered legislation, even unlawful legislation, the board has no authority to prevent it from being on the ballot,” he said.