Cynthia Nixon demanded Wednesday that the national Democratic Party denounce Gov. Andrew Cuomo after links emerged between the incumbent’s campaign and efforts to slime his challenger as “anti-Semitic.”

“This was not an accident. This was a strategy. Andrew Cuomo’s campaign sought to exploit our worst fears to score the cheapest and dirtiest of political points,” said top Nixon strategist Rebecca Katz.

Katz demanded that Democratic National Committee chief Tom Perez step in and address the mess: “The Democratic Party is smearing a Democratic candidate. What is he going to do about it?”

The statement came just a day after The Post revealed that a Cuomo campaign official repeatedly pitched allegations to a reporter at the paper on Friday that Nixon was tied to a movement calling for businesses to boycott Israel over its hotly contested settlements in Palestinian territories.

The Cuomo campaign cited a petition that Nixon signed with more than 200 other actors, directors and writers — including many prominent Jewish-Americans — that supported an acting troupe for refusing to perform in a West Bank settlement to back the claim.

The Post did not publish the story.

Nixon — a mother of two Jewish children and member of a Manhattan synagogue — says she does not support the boycott movement, but has said she would not bar its supporters from contracting with the state.

The next day, Saturday, a mailer paid for by the state Democratic Party landed in thousands of mailboxes making an almost identical claim as in the Cuomo campaign pitch. “With anti-Semitism and bigotry on the rise, we can’t take a chance with inexperienced Cynthia Nixon, who won’t stand strong for our Jewish communities,” the mailer said.

The backlash from Jewish politicians in New York began almost immediately. It was quickly followed by claims from Cuomo that he had nothing to do with the mailer. Instead, the governor pointed the finger at the state Democratic party, which he funds and controls.

Longtime political insiders cast doubt on the claims, pointing to Cuomo’s history of micromanaging and control of the party — he selected its current executive director.

Cuomo critics and allies described the mailer as potentially damaging and said it fits a pattern of alleged dirty tricks from the governor.

“I am voting for him. But this was so stupid,” said a veteran Democratic operative. “More than the mailer itself, this makes them look horrible. Plays to his worst parts. And it will hurt him.”