State Sen. Jessica Ramos — one of the fiercest critics of mayoral frontrunner Andrew Cuomo — will endorse the ex-governor Friday morning, effectively ending her struggling run for the seat.

The progressive Queens senator will throw her weight behind Cuomo at an 11 a.m. event at the District Council of Carpenters Headquarters, her campaign confirmed.

The backing is a sharp about-face from her critical public criticism of the former governor, who resigned in 2021 amid a series of sexual harassment allegations.

“People may want to be courteous to Cuomo’s face but they don’t forget the people he sent to die, the women he touched or the people he left in our streets needing mental health care and housing,” Ramos, 39, wrote on social media in late March.

In April, she also told The Post’s editorial board that people in political circles have been talking behind closed doors about Cuomo’s mental acuity.

“I don’t think the City of New York can afford a Joe Biden moment,” Ramos, referencing the president’s noticeable decline, said. “I think that there are real reasons why he’s not answering questions. Even when he went before Congress, he just can’t remember details about what he did.”

“His mental acuity is in decline,” Ramos repeated when pressed to clarify her allegation against the 67-year-old Cuomo.

In response, the Cuomo campaign insinuated the lawmaker was a drunkard.

“You can quote me rolling my eyes – this is a desperate attack from a desperate extreme left socialist who is in debt and polling at 3 percent,” Rich Azzopardi said.

“Was she sober when she said it?”

Ramos’s bid for the Democratic nomination never really got off the ground — even though she polled well earlier this year, despite name recognition.

The campaign has struggled to raise money, only able to bring in just under $300,000, and failed to reach the low threshold to unlock the city’s 8-to-1 public matching funds.

She currently has just $9,000 on hand.