ALBANY -- A coalition of Republicans and a dissident Democrat say they can take control of New York's Senate despite a 31-31 split with the Democratic conference by using a section of state constitution that they interpret as giving their leader two votes.

The latest challenge in a bizarre series of twists in the fight for control of the Senate comes as each side seemed unyielding.

On Wednesday, the coalition argued that the constitution provides Sen. Pedro Espada — who they say they elected Senate president on June 8 — one vote as a Bronx senator and one as acting lieutenant governor.

The constitution doesn't address the two-vote question. But Robert Ward, of the Rockefeller Institute of Government, said three constitutional experts in a 2008 symposium agreed the head of the Senate in this situation might just be entitled to two votes.

"On its face, the constitution does not rule out two votes," said Ward, author of the reference, "New York State Government."

He said the institute held a symposium last year after then-Lt. Gov. David Paterson vacated the office to succeed Gov. Eliot Spitzer.

"The conclusion was the two-votes argument just might be correct," Ward said.

When Spitzer resigned, then-Senate Majority Leader Joseph Bruno also asserted he had two votes. But with a solid and safe Republican majority, he never needed it.

The state constitution states that if there is no lieutenant governor, "The temporary president of the Senate shall perform all the duties of lieutenant governor during such vacancy or inability." The constitution also states that the lieutenant-governor, when acting in his or her duty as president of the Senate, has a "casting vote" in the chamber. That has been interpreted as applying to procedural matters, but it isn't detailed in the constitution.

Democrats who were ousted in last week's overthrow, however, say court cases suggest a second vote is not allowed. Spokesman Austin Shafran said a 180-year-old decision by the state's highest court, the Court of Appeals, ruled that the lieutenant governor can't vote to create a quorum, which is necessary before the Senate can vote on bills or resolutions.

"Our position is that it would not be lawful, but obviously it's something that could possibly have to be brought to the courts," Shafran said.

Espada said he didn't want to cast two votes Wednesday because that would draw more litigation and further delay any action in the Senate. Democrats have boycotted sessions since the overthrow. The regular session is scheduled to end Monday.

Espada said he thinks negotiations are progressing. But there was little public evidence of that.

The Republican leader of the coalition said Democrats must accept that they no longer rule the chamber.

"It's a necessity," said Republican Sen. Dean Skelos of Nassau County, who was elected majority leader by the group of 30 Republicans and two dissident Democrats in the surprise power grab. Skelos said the Democratic conference must recognize him as majority leader and Espada as Senate president.

"Based upon those conditions, I guess there won't be a discussion," said Sen. John Sampson of Brooklyn, new leader of the Democratic conference.

"We have offered them every possible compromise," said Sen. Eric Schneiderman, a Manhattan Democrat. "I think the public perceives all of us negatively, with little distinction. We're failing."

The Democratic conference insists the vote to install Skelos and Espada as Senate leaders was illegal — done after Democrats hastily adjourned — and so a new power sharing agreement is needed. They are pushing for a temporary solution, using alternating presidents and majority leaders, to get through the rest of the 2009 session and pass some critical bills.