With polling showing a tightening race for governor in solid-blue New York, a battle for the airwaves will intensify after Labor Day between Republican nominee Rep. Lee Zeldin and Democratic Gov. Kathy Hochul ahead of the Nov. 8 election.

“There’s a whole lot of Democrats that want to declare this race, dead and over with – but they ain’t seen nothing yet,” Republican state Chair Nick Langworthy boasted Sunday.

But it is the Democratic incumbent and her allies who are taking the first shots, The Post has learned

A union backing Hochul is touting her record in office in a new 30-second spot landing upstate and on Long Island Tuesday where a recent Siena Poll showed Zeldin with a single-digit edge.

The $300,000 ad blitz is part of a $1 million effort by a PAC backed by the North Atlantic States Regional Council of Carpenters to Democrats this November.

“History tells us the ad war is going to enter its hot phase this month,” political consultant Jake Dilemani told The Post Monday. “Depending where you are in the state, you’re about to be inundated.”

The incumbent Democrat’s campaign also threw down $2 million last week to launch a post-Labor Day air offensive that will begin reaching English and Spanish-speaking voters from Erie County to Montauk in the coming days.

Republicans are bracing for the barrage while preparing their own counter-offensive.

“When ad buys are made, everyone will know about it because it will be a matter of public record,” Langworthy said Monday.

“He’s nearing somewhere around a total of 15 million raised,” he added about Zeldin.

Zeldin has spent the weeks after his big primary win loading up on cash, with ]$1.5 million raised on Sunday alongside ex-President Donald Trump at a New Jersey fundraiser and $1 million more last week.

Republicans say they are aiming to provide the Zeldin campaign some air cover through advertising bought by outside groups like a PAC formed last month by former GOP state Chair Ed Cox, former Rep. John Faso and political operative Jason Weingartner.

“Despite Gov. Hochul’s pay to play corruption and eagerness to sell access to Albany, Congressman Zeldin is the best funded Republican challenger for statewide office ever,” spokeswoman Katie Vincentz said in a text Monday.

“Congressman Zeldin is going to have all of the resources he needs to Fire Kathy Hochul,” she added.

Campaign filings from mid-July showed Hochul, who has also raised millions in recent weeks, with $11.7 million on hand compared to $1.6 million for Zeldin, with both campaign declining to give total fundraising figures as of Monday.

The dueling campaigns are taking aim at each other with messaging highlighting their preferred issues ahead of midterm elections that will determine control of the U.S. House, the state Legislature as well as statewide offices like governor.

Zeldin has assailed Hochul for backing progressive policies like bail reform amid an ongoing rise in crime while challenging her to take definitive stands on issues like a proposed repeal of qualified immunity for police officers.

He has also tried to leverage alleged pay-to-play schemes involving the governor to transform her big cash advantages into a liability with voters.

But his own efforts to raise money have opened him to new attacks from Hochul, who took a shot at him Sunday for campaigning alongside Trump, who remains unpopular with many voters in his home state.

Zeldin appears to be gaining momentum in the race based on a poll released Sept. 3 that showed her with just a four-point lead over Zeldin in a state where registered Democrats outnumber their GOP counterparts by roughly two-to-one.

Other polls have shown Hochul with leads ranging from 24 points to 8 points – with a widely-respected Siena College poll showing Zeldin down 53% to 39% in early August.

The race for governor is entering a new stage following the Labor Day holiday and political experts say the race remains far from over with just over two months to go before the final votes are cast.

“I’d expect all pistons to be firing on the advertising front from both campaigns by mid month, and that will continue right up until election day. With summer over and schools beginning, the ad war begins in earnest,” Republican political consultant William O’Reilly told The Post Monday.