A big-time NYC real estate developer slammed Mayor Zohran Mamdani over his “ugly” political stunt outside Citadel CEO Ken Griffin’s apartment touting his pledge to tax the rich, The Post has learned.

“Ken is the one who can galvanize the business community,” Vornado honcho Steve Roth said on the earnings call Tuesday morning, according to a transcript.

“I would be first in line to support him. The ugly, unnecessary video stunt is personal to Ken and sort of personal to me too.”

The fresh-faced mayor picked a fight with the influential billionaire businessman last month when he dropped one of his signature social media reels using Griffin’s 24,000-square-foot pad on Central Park South as the centerpiece to tout Gov. Kathy Hochul’s proposed pied-á-terre tax.

The tax would put an additional levy on pricey second homes for non-New Yorkers.

Griffin, who met with Hochul last week for a private sitdown in Albany, took exception to being the poster boy of Mamdani’s tax-the-rich campaign, with business leaders calling foul about dragging the hedge fund manager who has injected millions of dollars into the Big Apple.

In response, Citadel COO Gerald Beeson called the attack “shameful” and even floated canning the $6 billion renovation of the company’s Park Avenue office.

Vornado is at the center of the development of that massive new spot building on Park Avenue and also owns most of the property around Penn Station.

“I must say that I consider the phrase ‘Tax the rich,’ quote ‘Tax the rich’ when spit out with anger and contempt by politicians both here and across the country, to be just as hateful as some disgusting racial slurs and even the phrase ‘From the river to the sea,'” Roth continued, referring to the hateful slogan that implies the destruction of the Jewish state of Israel.

“What these polls seem to be saying is that the rich are evil or the enemy or the targets, or maybe even just suckers,” he said. “But the rich whom the politicians are targeting started at nothing, are the epitome of the American Dream.”

Roth added that the company would “stand behind” whoever the mayor is, but hoped Mamdani would realize as mayor that the “hardworking 1% is allies, not enemies.”

Mamdani’s tax-the-rich agenda was a key pillar in his campaign to get elected mayor last year.