Nassau County Executive Bruce Blakeman challenged Gov. Kathy Hochul to draw a line in the sand Monday as she faces pressure from Democratic Socialists of America to back Mayor-elect Zohran Mamdani’s proposed tax hikes.

Blakeman, who is considering a run against Hochul in the gubernatorial election next year, argued that raising taxes could drive corporations out of the Empire State and potentially increase costs for consumers and small businesses.

“This is bad for Nassau County, this is bad for Long Island, this is bad for the Metropolitan region, and this is bad for New York State — we are going to fight very hard against it,” Blakeman told reporters in the county Legislative chamber.

“New York is already the highest taxed state in the United States,” he said, adding that New York should not be looking to New Jersey for inspiration on the tax code.

The recently re-elected Republican county executive was joined by officials and business leaders in the city’s neighboring suburb to demand Hochul stop any consideration she may be giving to Mamdani’s plans.

The democratic socialist has pushed for a 2% tax surge on millionaires and he also wants to hike the corporate tax rate from 7.5% to 11.5%, to match the Garden State.

Mamdani’s DSA allies — empowered and gaining mainstream influence after his win in the Big Apple mayoral election this month — have turned the heat up on Hochul, confronting her with “tax the rich” chants at recent appearances.

Hochul — while repeatedly publicly insisting she won’t raise income taxes — has reportedly signaled some openness to hiking the corporate tax rate.

Blakeman said Monday he worried such tax increases would be “trickled-down” to shoppers in the form of price hikes. 

“We are very concerned that this will drive more jobs out of New York State, that this will drive more businesses out of New York State, and that this will drive more residents out of New York state,” he added. 

A Long Island business making $5 million dollars per year — the income needed to be considered a corporation in the state — pays about $362,500 in corporate taxes currently, according to Nassau County estimates. 

Under Mamdani’s proposal, businesses making the same baseline would see a hike of roughly $212,500 in corporate taxes per year, Blakeman’s office said.

In the five boroughs, that figure would jump from about $805,000 to over $1 million due to city taxes if the proposal is implemented, according to the estimate. 

Leaving the state wouldn’t necessarily spare companies from the hit, explained David Adeoya, a Nassau County-based tax expert.

Under New York law, corporations can still be taxed locally if they continue doing business or make enough sales in the state — meaning a move across state lines doesn’t automatically cut their tax bill.

And in some cases, a company that relocates but still sells heavily into the state can be charged a higher rate, and in rare situations may even pay more on fewer sales due to how the state’s tax rules work.

Mamdani wants the tax increases to pay for his agenda, which includes universal child care, free bus service and city-owned grocery stores.

The DSA is demanding that Hochul back the policies of Mamdani, whom she endorsed in the mayoral race — or be voted out by a candidate who will in the Democratic primary for governor next summer.

“Over 1 million voters in New York made it very clear what we want,” DSA co-chair Gustavo Gordillo said Sunday at a rally in Union Square.

DSA member and Brooklyn state Sen. Jabari Brisport added at the rally that greenlighting the tax hike was Hochul’s last chance to win the left-wing group over before she strikes out and they back another candidate.

Hochul on Monday stressed that she still hasn’t reached a decision on the proposed tax hike, and is waiting for a “clear line of sight” on what next year’s budget may look like given the city’s deficit and threats from President Trump to halt federal funding.

“It’s November — January, we’ll have at least a clear view of what we’re in for the next session and the next year. So I’m going to be, not intentionally vague, but I had to be vague because we don’t have all the information” she said.