Gov. Cuomo gave the “I Know Nothing” defense when asked about the New York State Democratic Party mailer that slimed rival Cynthia Nixon as condoning anti-Semitism, while the party’s executive director issued an extraordinary statement offering to put out a new mailer to the same households to repair the damage.

But Nixon wasn’t letting team Cuomo off the hook.

She said that’s an empty gesture because it’s unlikely any mailer could go out before Thursday’s Primary Election.

“I wonder if it will be on Friday, September 14. It is a little late,” Nixon said.

“I think frankly Andrew Cuomo should do a robo-call saying that he is regretful that the New York State Democratic Party has put out this information calling me an anti-Semite or for being guilty of spreading anti-semitism and nothing could be further from the truth,” Nixon said Sunday.

For his part, Cuomo pleaded ignorance while condemning the anti-Nixon mailer.

“I didn’t know about the mailer. I heard about the mailer. I haven’t seen the mailer,” Cuomo said Sunday following the backlash.

But Nixon said “I categorically don’t believe” that the governor didn’t know about the content of the mailer put out by the state Democratic Party that he controls.

“He’s the head of the Democratic Party. He controls the state committee,” Nixon said.

She also called Cuomo’s Sergeant Schultz’s defense as “patently absurd.”

“I am the mother of Jewish children and I am very alarmed by the rise of anti-semitism in this country. I am frightened for my children. I am frightened for the world,” Nixon said at a press briefing in Brooklyn accompanied by Councilman Jumaane Williams, who is running for lieutenant governor and Councilman Brad Lander.

“And to use this kind of unfounded charge, this political weapon, this smear campaign is unworthy of Andrew Cuomo’s Democratic Party,” said Nixon, who is heading to synagogue tonight to celebrate the Jewish New Year.

Democratic Party executive director Geoff Berman issued a statement of regret and offered to try to undo the damage.

“The State Party sent out a wrong and inappropriate mailer — will work with the Nixon campaign to send out mailing of their choosing to the same universe of people.”

A Democratic Party source said the mailer was sent to 7,000 targeted households, likely areas where ultra-orthodox Jews reside.

The mailers appears to be part of the $136,000 campaign by the state Democratic Party to boost Cuomo in the run-up to the Sept. 13 primary.

Campaign finance filings show the state Democratic Party — funded by a massive $2.5 million infusion from Cuomo’s campaign account last month — cut six checks to Mission Control, a political mail and consulting firm based in Connecticut during the last few weeks in August.

The firm is headed by Ed Peavy, who handled Cuomo’s political mailers in 2010 and 2014 campaigns.

The party mailer said, “With anti-semitism and bigotry on the rise, we can’t take a chance with inexperienced Cynthia Nixon.”

It also accused her of being “silent on the rise of anti-Semitism” and being a supporter of the Boycott, Divestment and Sanctions movement against Israel.

Nixon on Sunday said she opposes the BDS movement and supports a “two-state solution” between Israel and Palestinians. But she said unlike Cuomo, she wouldn’t “blacklist” people who support BDS. Cuomo signed an executive order barring state entities from doing business with firms that support BDS.

Cuomo meanwhile said he regretted the party’s smear against Nixon.

“The way I’ve ran this campaign, it’s been on the issues, it’s been positive. I think the mailer was a mistake. I think it was inappropriate,” the governor said

Cuomo said state party officials “better figure out how this happened and make sure it doesn’t happen again and insisted, “I don’t deploy those negative tactics, and I don’t want the Democratic Party of the state doing it.”

But critics have long complained that Cuomo and his father, former Gov. Mario Cuomo, fight dirty.

Former Mayor Ed Koch blamed the Cuomos for “Vote for Cuomo, not the Homo” signs that were distributed in the 1977 race for mayor that pitted Mario against him. Andrew helped run his dad’s campaign.

Both Cuomo denied having anything to do with the anti-gay play placards.