A GOP insider says “titans of industry” at New York City are threatening to withhold donations to the New York Republican Party if they don’t force a mayoral nominee, Curtis Sliwa, to drop out of the race.

“They’re really considering not supporting the state party. It does not mean that they will not support a candidate,” a former New York GOP finance chairman, Arcadio Casillas, tells The New York Sun. “Would you invest in something that you feel you’re not going to get a return or you’re going to lose every penny you put into it?”

This threat of withholding funds comes as business leaders panic over the likely possibility that a 33-year-old state assembly member, Zohran Mamdani, will be the next occupant of Gracie Mansion. Mr. Sliwa’s longtime employer at WABC radio, John Catsimatidis — who ran for mayor as a Republican and has large sway with the party — called on Mr. Sliwa to drop out on Monday to give Governor Andrew Cuomo a better shot at winning.

“Curtis should pull out right now,” Mr. Catsimatidis said on his radio show Monday morning. “People will be proud of him that he did the right thing for New York City.”

“We cannot take a chance on Zohran winning,” he said.

Mr. Sliwa is defiant. He won the Republican nomination unopposed, while Mr. Cuomo ran and lost in the Democratic primary and is now trying to push out a major party candidate. Mr. Cuomo called Mr. Sliwa “a spoiler” on Sunday — a term normally reserved for a third-party candidate.

“Let’s be very clear: I am not dropping out. Under no circumstance. I’ve already been offered money to drop out, I said no,” Mr. Sliwa said Tuesday morning outside the West 72nd Street subway station.

Mr. Sliwa also called billionaire hedge funder Bill Ackman, who called on Mr. Sliwa to drop out, “a jerk” who knows nothing about politics. “He lives in Chappaqua, the whitest suburb of America, where even the lawn jockeys are white,” he said.

The calls for Mr. Sliwa to drop out of the race are not new, but they are ramping up with only two weeks to go before Election Day. Early voting starts on Saturday.

Mr. Mamdani is leading in all major polls by double digits. In a city where Democrats outnumber Republicans by six to one, this is expected — yet Mr. Mamdani’s radical policy proposals and Mr. Cuomo running as an independent are the wild cards.

Since Mr. Mamdani’s upset win in the Democratic primary in June, moderate Democrats, independents, and some Republican business leaders have been pushing for this to become a two-person race. Their thinking is that the only way to beat Mr. Mamdani is to consolidate the anti-Mamdani vote.

The Sun spoke with several of these business leaders and politicos over the summer, and they said to wait until after Labor Day to see movement. Then, in September, they said to wait two weeks. Mayor Eric Adams then dropped his re-election bid. Getting Mr. Sliwa to bow out is proving more difficult. Time is running out.

“It’s too late,” Mr. Casillas says about the effort by billionaires to influence the election, though he hopes Mr. Cuomo can eke out a win. Another politico tells the Sun that these billionaires “should have put their money where their mouth is” — and they should have done it earlier.

Mr. Cuomo’s campaign is highlighting a new Gotham Polling/AARP poll released Monday that shows the former Empire State governor trailing Mr. Mamdani by only 3.9 points — within the 4-point margin of error — if Mr. Sliwa drops out of the race. If Mr. Sliwa stays in, Mr. Mamdani wins by 14 points, according to the poll. Mr. Sliwa is polling consistently at just below 20 percent support.

“As New Yorkers see this reality, they’ll discard the spoiler Curtis Sliwa and rally behind Cuomo to save the city,” Mr. Cuomo’s spokesman, Rich Azzopardi, said in a statement.

A problem with this poll, though, is that it used 2021 turnout demographics, when Mr. Mamdani mobilized new and infrequent voters to the polls for his upset primary win. His voters are far more committed and enthusiastic about their candidate than are Cuomo voters, according to polls. Mr. Mamdani has also effectively used social media and the Democratic Socialists of America to mobilize volunteers to get out the vote.

Mr. Cuomo, meanwhile, is relying on super PACs and has taken more days off from public campaigning since Labor Day than the other candidates, according to an analysis from the New York Post. One strategist who spoke to the Sun described Mr. Cuomo as “phoning it in.” Another who supports Mr. Cuomo questioned why he didn’t bring more fight to last week’s debate.

A Democratic strategist, Michael Hardaway, tells the Sun he has doubts the Sliwa vote would all go to Mr. Cuomo. “I don’t think we should assume that,” he says.

Political insiders tell the Sun there were a lot of meetings among business leaders during the summer and fall about how to stop Mr. Mamdani from winning. In the past week, a handful of businessmen donated more than $3 million to super PACs to help Mr. Cuomo and to try to prevent a Mamdani win. The question many are asking is where is this money going and whether it is being spent effectively. And why didn’t big-dollar donations come in over the summer — and with them a concerted anti-Mamdani media strategy?

When the Sun in September spoke with President Trump’s pollster, John McLaughlin, he said the only way to beat Mr. Mamdani would be to increase his unfavorability rating with a targeted campaign. Why didn’t this happen earlier? Now, prominent Republicans are divided on whether to support Mr. Sliwa or Mr. Cuomo. Some, though, admit that it now seems like a lost cause.

Mr. Sliwa is not backing down, and he has the support of the five New York Republican Party county leaders, representing each borough. The Manhattan chairwoman, Andrea Catsimatidis, is John Catsimatidis’s daughter.

“Republican voters are not going to vote for Andrew Cuomo,” the five GOP county leaders wrote in a joint statement. “He lost his own party’s primary badly and is not even appearing on the ballot on a major party line. Republicans should not have to clean up the mess Andrew Cuomo and the Democrats created, and we will not allow the political class to interfere with voters or hijack our ballot.”

“It’s completely unfair, rude, vulgar, disrespectful that he’s being asked to step down,” the chairman emeritus of the Brooklyn Republican Party, Richie Barsamian, tells the Sun. “He’s a living legend to New Yorkers. He and his red beret are as recognizable to New Yorkers as the Statue of Liberty.”

The current Brooklyn Republican Party chairman, Liam McCabe, tells the Sun Mr. Cuomo is the one who should drop out. “He has no shame, Andrew Cuomo. He should drop out,” he says. “You are witnessing the collapse of the once great Democratic Party, the Democratic Party of my father, the party of JFK, even of Clinton.”

Mr. Mamdani is relishing in this fight and has a vested interest in keeping both Messrs. Sliwa and Cuomo in the race. “I never thought I would say this, but here we are, where the only candidates who agree that billionaires shouldn’t control the future of this city are the Republican nominee and the Democratic nominee,” he said.