ALBANY, N.Y. (AP) — New York Gov. Andrew Cuomo on Wednesday urged a rogue Democratic lawmaker to end his alliance with Republicans and allow Democrats to lead the state Senate as the battle for control of the chamber escalates ahead of the fall elections.

Democrats won two special Senate elections Tuesday, giving them 32 members in the 63-seat Senate. But Republicans are expected to stay in control of the Senate at least until the end of the legislative session in June because of the support of Sen. Simcha Felder, a registered Democrat who nonetheless sits with Republicans.

Cuomo released a public letter to Felder on Wednesday urging him to reconsider. He later told reporters that Felder's decision to deprive his own party of Senate control allows Republicans to block proposals to strengthen gun control laws, reform the state's antiquated voting rules or rein in the state's lax campaign finance laws.

"It's on all him," Cuomo said of Felder. "This pressure, it's all on him. Depending on what he does, will make a major difference on major issues."

Felder announced his intention to stay with the GOP on Tuesday, ending weeks of speculation about whether the Democrats would take over the Senate if they prevailed in Tuesday's elections. As an explanation, Felder said he didn't want to create political chaos in the Senate in the final two months of the legislative session. On Wednesday, Felder said he had not yet read Cuomo's letter. When asked by reporters if he was open to reconsidering his decision, he refused to rule out the possibility.

"I never say never," he said.

Senate Democrats say they will now focus on winning enough seats in November to win a clear majority and make Felder's decision irrelevant. But Republicans vowed to fight to preserve their hold on the Senate, which they have controlled for nearly all of the last 80 years. Democrats already control the Assembly and hold the offices of governor, attorney general and comptroller, making the Senate the last bastion for Republicans.

Senate Republican spokesman Scott Reif said voters appreciate having the Republicans in charge of the Senate as a counter balance to downstate Democrats.

"The New York City politicians who think it will be easy to flip the state Senate and impose their radical agenda on the people of New York should take heed," Reif said. "We are ready for this fight and fully expect to retain our majority in November."