Mayor Anthony A. Williams sought to assure D.C. Council members and residents yesterday that the city will spend no more than $535 million on a baseball stadium complex along the Anacostia River in Southeast, dismissing reports that the projected price now exceeds $700 million.

"Under no circumstances will this stadium cost $700 million," Williams (D) said at a midday news conference at the John A. Wilson Building. Fears of higher costs, he added, are being generated by "a vocal minority who have been against baseball from day one."

Williams's comments came a day after city sources revealed that D.C. Chief Financial Officer Natwar M. Gandhi had said in a private meeting with the mayor and other city leaders that the cost of the stadium, with infrastructure improvements and bond financing fees, could rise to as much as $714 million.

Gandhi's previous estimate was $535 million, with an additional $54 million in bond financing fees, for a total of $589 million. City officials acknowledged last month that $55 million of infrastructure projects originally part of the total cost had been taken out of the budget because the ballpark has become more expensive.

"Costs have soared, and we have not even put a shovel in the ground," D.C. Council member Adrian M. Fenty (D-Ward 4) said yesterday during a council discussion about the project's costs. "Wait until we start building this thing."

Although costs related to the project have increased, Williams said, it is misleading to assume that the city's costs will increase. Instead, Williams said, the city will seek funds from the federal government and developers to pay for all items -- including upgrades to roads and Metro facilities -- outside the $535 million the city has committed to the project.

"I never believed these costs should be borne completely by the baseball stadium budget," Williams said. "They never have been borne completely by other cities with stadiums."

He added that he does not consider the $54 million in financing fees to be part of the budget because those fees will be paid with revenue generated for the city by the Washington Nationals' first season and interest earned on the stadium bond funds before they are spent. However, council members have disputed Williams's explanation, saying they believe that the financing fees were included in the original budget.

Gandhi is conducting a study that compares the costs of building at the Anacostia waterfront site to a location near Robert F. Kennedy Memorial Stadium and is expected to deliver his report to the mayor and council Friday. He has declined to comment publicly on his analysis.

The report could be critical to the project because the council, which is scheduled to vote Dec. 20 on a stadium lease agreement between the District and Major League Baseball, has grown increasingly concerned about costs.

Eight of the council's 13 members voted in favor yesterday of a bill offered by David A. Catania (I-At Large) that would force the mayor to pay for all infrastructure improvements within the $535 million budget. However, the measure, which needed nine supporters because it was offered as an emergency bill, failed by one vote. The mayor "thinks that if he says it enough, then it will be true that the stadium costs only $535 million," Catania said. "But it's a lie. It's patently untrue."

Asked to comment yesterday on cost estimates of more than $700 million, President Robert A. DuPuy of Major League Baseball said: "I believe the mayor indicated that number was not comparable to the numbers we have been working with. Without having the opportunity to study Dr. Gandhi's report, it's hard to really comment in detail. But we do not believe it represents an accurate number."

During the lease negotiations, which city officials said could be completed by Friday, Major League Baseball has agreed to concessions to gain more council support. Baseball negotiators recently agreed to give the city a letter of credit that would cover the Nationals' rent for one or two seasons in case of a terrorist attack or players' strike and a $20 million payment toward stadium construction. In return, the city has agreed to give baseball one-third of the parking revenue generated at the stadium on non-game days.

Council Chairman Linda W. Cropp (D), whose support for the stadium project is considered crucial by ballpark boosters, voted against Catania's bill. She said she wants to review Gandhi's new cost study before deciding whether to support the stadium lease deal.

Williams and top aides insisted that the $714 million includes items that are not in the project's budget and that probably would be funded from other sources.

For example, the city is planning to build two above-ground parking structures at the stadium for $21 million. But Gandhi has said $41 million may be needed on top of that because city zoning laws require underground lots at the waterfront location. If the city builds underground lots, developers who are eager to help establish an entertainment district around the stadium will pay for it, Williams said.

Similarly, mayoral aides said, the federal government, which is building a Department of Transportation building near the stadium site, is expected to help fund the $20 million Gandhi has earmarked for upgrading the Navy Yard Metro station. But when pressed to specify which federal agencies he has contacted for money, Williams said: "I never said the feds will pick up the whole tab. We're looking everywhere for possible sources of revenue."

Gandhi's latest analysis includes $40 million in new contingency money, in case costs rise again during the two years the stadium is under construction. That is about twice the amount that baseball recently agreed to contribute. If Gandhi insists on the higher figure, the city could be forced to ask baseball for another contribution, government sources said yesterday.

Staff writer Barry Svrluga contributed to this report.

Mayor Anthony A. Williams said the stadium project budget is being unfairly burdened with costs that will be paid for with money from other sources.