Cynthia Nixon blasted Gov. Cuomo on Monday for “mansplaining” about sexual harassment and for enlisting a lawmaker accused of forcibly kissing a female staffer to combat misconduct against women.

The former “Sex and the City” co-star played the gender card one week after announcing she would challenge Cuomo for the Democratic gubernatorial nomination in the Sept. 13 primary.

“I have seen Andrew Cuomo mansplaining and lecturing women on sexual harassment,” Nixon said at a press conference in Albany. “I have read about him lecturing [state Sen.] Andrea Stewart-Cousins that [state Sen.] Jeff Klein is more qualified in understanding suburban voters, better than she does, despite her being a Senator who oversees the suburbs of Westchester.”

Nixon also brought up a recent sexual-harassment allegation against Klein, leader of the renegade Independent Democratic Conference (IDC) that shares power with the Senate’s Republican minority.

“At a time when millions of women are making their voices heard, why should we settle for sexual-harassment policies that are being discussed behind closed doors without a single woman present?” Nixon said at the Albany Hilton.

“The governor’s backroom deals have left us with a situation where Andrea Stewart-Cousins, the leader of the Senate Democrats, the highest-elected woman in New York state, is not in the room, but the king of the eight-member IDC — Jeff Klein, who is accused of sexual misconduct himself — is,” Nixon said.

In January, former IDC policy analyst and counsel Erica Vladimer accused Klein of unexpectedly kissing her while they were smoking cigarettes outside an Albany bar following passage of the state budget on April 1, 2015.

Klein has denied Vladimer’s allegations.

Klein spokeswoman Candice Giove responded by saying, “Senator Klein is in lockstep with Democratic Leader Andrea Stewart Cousins, and the 25 additional Democrats” who all voted in favor of a bill overhauling the state’s sexual harassment policy.

Cuomo’s office insisted Senate Democrats are “fully represented” in discussions on the bill.

A spokesman for Stewart-Cousins denied that, saying Senate Democrats had been “shut out” of ongoing negotiations.

Nixon also attacked Cuomo on corruption, but mostly ducked questions about her ally Mayor de Blasio.

“I’m running for mayor, not governor,” she said before correcting herself.

“I think we have a very different situation,” Nixon added. “The important thing to remember here is we have a governor whose chief aide was not accused of corruption, but was actually convicted of it.”

De Blasio was investigated by state and federal prosecutors, who accused him of shady fundraising practices, but didn’t file charges.