Socialist mayoral candidate Zohran Mamdani was chased out of Lower Manhattan by a serial City Hall gadfly who slammed him as an “antisemite” — and got into a shoving match with the politician’s staffer.

The enraged protester, identified by sources as Raul Rivera, 55, of the Bronx, followed Mamdani as the pol was ushered by security into his waiting SUV, video of the encounter shows.

Rivera — who was arrested in June for allegedly biting a Mamdani campaign volunteer — shouted and cursed as Mamdani ignored him and climbed into the vehicle, the footage shows.

Mamdani had been in Foley Square for a protest where he and other lefty pols and activists stood in support of state Attorney General Letitia James as she faces federal charges of bank fraud and making a false statement to a financial institution.

“Antisemite! Denounce Sharia law! Denounce Hezbollah! You can’t do it!” shouts Rivera, while, Mamdani with his back turned, approaches the black SUV.

“Walk the narrow or you’re going to jail with Tish!” he screams before Mamdani enters the vehicle.

A member of Mamdani’s team intervened after Rivera walked too close to the vehicle and shoved him away after the agitator screamed Mamdani is a “f–king rat.”

The much-shorter Rivera, sporting a baseball cap worn backwards, pushes the man back several times while holding what appears to be a President Trump flag, repeatedly yelling “Get the f—k off me, bro!”

Public advocate Jumaane Williams, who was not engaged in the mayhem, approached the camera to capitalize on the attention.

“One of the good things is we’re out here to allow people like this to do this. In an authoritarian regime, they’d be thrown away, but we protect everybody — including them,” Williams says in the clip before throwing up a peace sign.

A woman driving the vehicle could be heard yelling at Rivera to “get a job” shortly before zooming away with Mamdani.

Rivera is a thorn in the side of both lefty and conservative city and state pols, repeatedly showing up and events to heckle them.

“He harasses everyone,” said a Democratic councilman. “He’s a loser.”

Rivera allegedly attacked a 29-year-old woman volunteering for Mamdani in June by biting her on the hand at a Lower Manhattan news conference.

The woman was taken to the hospital for treatment, and Rivera was arrested and charged with assault, PIX-11 first reported.

Rivera confronted Mamdani at that event, accusing him of being anti-Israel, and allegedly bit the volunteer when she intervened.

Rivera on Friday was apparently demanding answers from Mamdani after he used the second anniversary of Hamas’ Oct. 7 terror attack to blast the Israeli government for launching a “genocidal war” in Gaza, for which the US “has been complicit through it all.”

Mamdani accused the Jewish state and Prime Minister Netanyahu of apartheid against the Palestinian people, drawing intense rage from both Democrats and Republicans.

The mayoral frontrunner declined to comment on the latest incident, and Rivera could not immediately be reached for comment.

Mamdani has come under fire for refusing to disavow his past use of the phrase “globalize the intifada” — but has taken great pains since to emphasize his support for Israel and denounce antisemitism.

The confrontation came just moments after Mamdani defended James against the Trump administration, calling the mortgage fraud indictment against her politically motivated vengeance.

“This is a blatant miscarriage of justice. This is a shameless act of political retribution,” Mamdani seethed about the federal charges  unveiled Thursday against James.

“And instead of prosecuting Tish James for doing her job, Donald Trump should be doing his.”

James won a civil judgment against the president and Trump Organization last year for inflating the value of his real estate empire, leading to $355 million in penalties that were ultimately thrown out after an appeal and Trump’s white-hot ire.