With speculation heating up that the City Council will attempt to vote to extend term limits, a 1961 Buffalo court case is on its way to the center of the fight.

After years of scant mention, the case — in which the state Court of Appeals ruled that Buffalo’s council could repeal a term limits law passed by referendum — is again being talked about around City Hall, where it is cited as evidence that New York’s council has the authority to extend its term limits, even though New Yorkers twice voted in favor of a two-term limit.

Even with that ruling backing a council’s right to vote to extend term limits, a flurry of legal challenges is expected to follow any effort to overturn the law. It could inject confusion into the 2009 races if candidates running for public office are uncertain as to whether they can run for a third term in their old seat or need to turn their attention to a new political job.

A senior attorney for the New York Public Interest Research Group, Gene Russianoff, said it would be “undemocratic” for the council to overturn a ballot initiative approved by city voters, and said there was a “good chance” his group would join a fight against such a vote in court.

For all the comparing of the Buffalo case with a potential term limits vote in New York City, he said there are two key differences between the scenarios. The first is that the 1961 Buffalo case dealt with a council overturning a term limits law for the mayor — not ruling on term limits for its members, he said.

If New York’s council takes up the issue of term limits, it would be expected to extend term limits for its members, as well as for the mayor.

The second difference relates to the timing of the votes, he said. While the Buffalo council voted to amend a term limits law that had been approved by referendum decades earlier, the New York City Council would be attempting to override a decision made by city voters in 1993 and again in 1996.

“I think there’s a big difference between a 35-year-old referendum from an earlier generation and something that has been approved by the voters” more recently, Mr. Russianoff said.

The talk about extending term limits by way of a council vote has soared in the past few days, after Mayor Bloomberg switched his stance on the issue and said he would consider signing a council bill that would allow him to run for a third term. The speaker of the council, Christine Quinn, is a longtime opponent of term limits, but last year appeared to have closed the door on the issue when she said she wouldn’t support any plans to change the term limits law.

An election lawyer at Stroock & Stroock & Lavan, Jerry Goldfeder, said that if the council did extend term limits, it would be difficult to mount a strong legal argument against the vote. He disagreed with the notion that an extension of term limits now would infringe upon the rights of candidates running for public office in 2009.

“It would obviously change the political landscape dramatically, but no candidate would be prohibited from running for an office for which they had been raising money,” he said. “There would just be additional candidates, including, perhaps, incumbents.”

A former director of the New York Civil Liberties Union, Norman Siegel, said that while the council “probably” has the legal right to extend term limits, it would face a fight from the public.

“If the mayor and the speaker engage in an unholy alliance to undo the people’s will, I think there will be people throughout the city who will be angry about that,” he said. “There would be a political backlash for people who went and did it.”