A majority on the D.C. Council is demanding a vote on a stadium lease between the city and Major League Baseball, and several council members said they will reject the deal unless baseball agrees to pay for any cost overruns on the project.

Baseball officials and District representatives have been negotiating for three months over the lease agreement, which will set the terms by which the Washington Nationals rent the ballpark to be built in near Southeast. Meanwhile, council members have grown impatient with the talks' slow pace, which has held up the sale of the team, and are worried that rising project costs will force the city to spend more than the $535 million approved last year.

The council passed the stadium financing package last year by a vote of 7 to 6, but since then, three stadium supporters on the council have been replaced by members critical of a publicly financed ballpark. A vote on the lease would mark the first time that the new council has taken a crucial action on the project.

Until recently, Linda W. Cropp (D), the council chairman, said that any decision to submit the lease to a vote hinged on an opinion from the D.C. attorney general as to whether the council was required to act on the agreement. But Cropp, who has yet to receive the opinion, said this week that she might bring the lease forward for a vote no matter what the attorney general recommends.

"I have no problems dealing with the lease through this council," Cropp said.

Seven council members, not including Cropp, said in interviews this week that they will insist on a vote. Several of them also said they will not approve any city expenditures above $535 million and will expect either baseball or a new Nationals owner to pay additional costs, including for infrastructure.

"I'm not prepared to continue being one of the biggest baseball boosters in the city without taking a look at that lease," said Sharon Ambrose (D-Ward 6), who voted in favor of the financing package last year. "Baseball is something the city really wants, but nobody wants it at any cost. . . . Wouldn't you think baseball wants a snazzy, attractive stadium in the nation's capital? Well, guys, ante up a little bit."

Cropp, who in the past has swayed the votes of some of her colleagues on the stadium issue, agreed that the council has an important role to play at this stage.

Asked whether the council should try to improve the deal the city gets with baseball officials, Cropp said: "There are opportunities to make it better, yes. The city needs to keep pushing and continue to drive a hard bargain here."

She also said that if stadium costs rise too much and baseball does not agree to contribute toward cost overruns, city leaders should "go back and renegotiate [the] site."

Cropp last year suggested that building a new stadium at the site of Robert F. Kennedy Memorial Stadium could save up to $200 million, although she ultimately endorsed the current plan.

Nationals President Tony Tavares declined to comment yesterday. But baseball officials have insisted that the stadium deal they struck with Mayor Anthony A. Williams (D) in September 2004 stipulates that the District is responsible for overruns.

Last week, D.C. Sports and Entertainment Commission officials acknowledged that because the new ballpark will be more expensive than expected, they have been forced to remove $55 million in infrastructure improvements -- including the repaving of nearby roads and expansion of a Metro station -- from the stadium budget. They said they would ask the federal government and private developers to cover those costs.

Meanwhile, baseball officials involved in stadium lease negotiations with the sports commission have taken a hard line on the city's financial demands. They have balked at the commission's demand for a $24 million letter of credit that would cover the Nationals' lease payments in case of a terrorist attack, natural disaster or players strike. And so far they have resisted the commission's request that baseball contribute $20 million to pay for underground parking.

Council member Kathy Patterson (D-Ward 3), who voted against the stadium financing deal last year, said: "I am prepared to support the deal we made a year ago that was $535 million, but when we add the Metro and other costs, I think that needs to be out front and explained, and we need to know what we're getting into. And I think that there needs to be more support from a new owner or from Major League Baseball."

Council member Jim Graham (D-Ward 1), who also voted against the project last year, said: "I cannot imagine why the lease would not be submitted to the council. If it is submitted as a bad deal, I can't imagine it being approved."

On Monday, the council will hold an oversight hearing on baseball matters at the John A. Wilson Building.

The council's involvement in the lease represents a setback for the mayor, the sports commission and baseball, all of which had been operating under the assumption that any lease agreement reached by the negotiators would be locked in place.

Mayoral spokesman Vince Morris said that Williams will abide by whatever Cropp decides on whether the lease will receive a vote from the council.

But Morris added that "the plan has already been approved by the council once, the overall agreement, and we've kept the council up to speed every step of the way and kept within the parameters of the original agreement."

Under city law, the council votes on all contracts that would cost the District $1 million or more. However, in the case of the stadium lease, the city will receive money through a $6 million annual rent payment from the Nationals.

Traci Hughes, a spokeswoman for the D.C. attorney general, said the office received a copy of the current lease language last week and is still reviewing whether the council is required to vote.

The council had an opportunity to vote on significant baseball legislation earlier this month when three technical amendments were proposed to correct inaccuracies in the stadium financing deal. Some members said before the vote that they would seek to reopen last year's agreement and get more money from baseball.

But Cropp vowed to block such motions, and the council approved the amendments 11 to 2, with only David A. Catania (I-At Large) and Adrian M. Fenty (D-Ward 4) voting against them.

Staff writer Thomas Heath contributed to this report.

Chairman Linda W. Cropp said this week that she might put the stadium deal to a council vote even if the city attorney general says it is not required.