A proposal by D.C. Mayor Anthony A. Williams to build a major league baseball stadium with public funds is proving extremely unpopular among District residents, according to candidates campaigning for city offices and a recent poll of likely Democratic voters.

The poll, conducted in June by the Service Employees International Union, which opposes the proposal, found that 70 percent of those surveyed oppose public funding, and more than half strongly oppose it. Using tax dollars to build a baseball stadium is particularly unpopular among women, Latinos, the poor and the elderly, the poll shows, but more than two-thirds of whites and men also oppose it. The survey of 571 people who said they are likely to vote in the Sept. 14 Democratic primary has a margin of error of 4 percentage points.

Word of the survey's unfavorable findings has spread around town in recent days, as baseball officials enter the final stages of negotiations over where to relocate the financially troubled Montreal Expos. Key members of baseball's relocation committee met Tuesday with District officials and yesterday with officials from Northern Virginia, who are also vying for the team.

A publicly funded stadium is a top priority for baseball Commissioner Bud Selig, who is expected to make a decision before the season ends in October.

Williams (D) has vowed repeatedly to come up with more than $300 million for a stadium within days of getting the nod from baseball. Yesterday, he played down the survey results, saying public opinion would shift rapidly if the city got the Expos and city officials had a chance to explain their proposal.

"It's difficult to talk about in the abstract," Williams said in an interview. "I mean, everyone is for baseball. Nobody's for robbing the schools and health care to pay for it. But that's not what we're talking about doing. I think we're able to do both."

Williams acknowledged that his stadium plans are "controversial" and have been from the moment he announced this spring that he was prepared to fully finance a new ballpark. Williams has declined to release details of his plan. Generally, however, he is proposing to sell bonds to finance stadium construction and repay the debt -- at a rate of about $25 million a year -- through a combination of dedicated taxes, including sales taxes on stadium-related items such as parking, souvenirs and tickets, and a new tax on business.

D.C. Council Chairman Linda A. Cropp and finance committee Chairman Jack Evans strongly support the mayor's proposal and have said they can rally a majority of the 13-member council behind it. Because none of the money would come from current city revenue, Williams and his supporters contend that building a ballpark would have no impact on city services. Those surveyed apparently don't understand that, Williams and Evans said.

"Are they against taxing businesses -- who want the tax -- to pay for the stadium? Keeping in mind that I will not put that tax in place for any other reason?" Evans said. "They probably wouldn't be if they understood what they were talking about."

But opponents of public stadium financing say it's wrong to use city resources of any kind to build a baseball stadium when the city has so many more pressing concerns.

"The lines are incredibly long at Southeast General Hospital, and here we are talking about expanding our bonding capacity and spending political capital for a baseball stadium," said Jamie Kendrick, executive director of the SEIU Maryland-DC State Council. "I mean, if business were saying tax us for a new hospital or a major school improvement program in addition to baseball, there might be something to discuss. But clearly, that's not where they are."

The SEIU survey suggests that support for a publicly funded baseball stadium has eroded over the past two years. In May 2002, a Washington Post poll found that 84 percent of city residents favored returning big league baseball to the city, but they were split down the middle on whether taxpayers should help pay for a ballpark.

SEIU, which represents more than 10,000 people who live or work in the District, opposes public stadium financing. The labor union's survey included two questions about baseball on a broader poll about city politics conducted at the end of June.

Those surveyed were first asked whether they "favor or oppose building a baseball stadium with public funds." Thirty percent said they favored that plan, while 62 percent opposed it and 8 percent were undecided.

Those polled were then told that "Williams and D.C. business leaders" say a baseball team and stadium would "increase pride in the city, bring new businesses and jobs, and help revitalize the neighborhoods." Opponents, meanwhile, "say that the economic benefits are exaggerated and that city money should go to more important needs like the police, schools, health care and street repair."

On the second question, support for public financing fell to 23 percent, while opposition rose to 70 percent. Six percent were undecided.

"We think that baseball would be great for the District," Kendrick said. "But I think we ought to find a way to proceed that requires private investment."

While the poll is two months old, the debate over how to pay for a ballpark is figuring prominently in some campaigns for the D.C. Council, now shifting into high gear in advance of the Sept. 14 primary. At a candidate forum sponsored by AARP, for example, two Democrats vying to replace at-large council member Harold Brazil (D) drew approving murmurs from the audience when they said they would oppose public funding.

Brazil, who supports it, promised to make sure the city would "not use any money that's in the treasury today."

Brazil is a key figure in the stadium debate. As chairman of the council's committee on economic development -- and a member of Evans's finance committee -- his vote would be needed to pass a tax on business.

Yesterday, Evans urged baseball officials to make a decision fast, before D.C. voters have a chance to change his committee's composition. In addition to Brazil, Evans's committee includes Kevin P. Chavous (D-Ward 7), who faces a tough race against former human services director Vincent Gray.

"We better get this done before January 1," Evans said. "Clearly, if they both lose, yeah, we got a different ballgame."

Mayor Anthony A. Williams says financing the stadium would not take away from services.