Bronx prosecutors who downgraded charges against an ex-con accused of sucker-punching a man into a coma — helping to free the suspect — asked a grand jury Tuesday to now upgrade the raps.

Cops had arrested suspect Van Phi Bui, 55, for attempted murder in the horrific Aug. 12 attack, only to watch as the DA reduced the charges to non-bail-eligible misdemeanors, claiming that was all the evidence allowed at the time.

Bui, a convicted sex assaulter, was then cut loose with no bail on the misdemeanor charges of assault and harassment in the beat-down, creating an avalanche of criticism captured by a Post front page — and leading Gov. Kathy Hochul to finally step in.

The governor ordered Bui to be rearrested and held, saying his bust in the attack was a violation of his lifetime parole for the sex conviction.

Bui was back in court Tuesday for a scheduled hearing in his assault case. The Bronx District Attorney’s Office told the judge it is asking a grand jury to have the misdemeanor charges against the suspect upgraded to a felony.

A felony charge would be bail-eligible and could help keep Bui behind bars while also increasing any potential prison time for him if he is convicted. It was not clear what the sought felony charge was or how many felonies Bui could face.

The grand jury was considering the prosecution’s request Tuesday, with Bui declining to testify, a Bronx DA rep said after the court hearing.

“The investigation gathered evidence which is before the grand jury,” the spokesperson told The Post in an email, in response to a question about what had changed since the initial charges. “It will decide if the defendant should be charged with a felony.”

A previous lawyer for Bui said at a recent parole hearing that it would be unfair for his client to face upgraded charges, claiming such raps would be the result of “outside pressures from the press and the governor.”

The suspect’s current lawyer, Casey Trimble of the Legal Aid Society, appeared in court Tuesday with a black leather briefcase with silver lettering that read “Free Them All.”

He objected to courtroom photography by The Post, calling articles covering his client “grotesque” and “tantamount to character assassination.”

Trimble opposed prosecutors’ request Tuesday to amend the already in-progress order of protection for the 52-year-old victim, Jesus Cortes, to include the pummeled guy’s family, who live in the same neighborhood.

“[Bui] has no interest in contacting members of [Cortes’s] family,” Trimble said.

Judge Srividya Pappachan left the order of protection in place solely for Cortes.

Cortes’ brother, Juan, broke down crying at hearing his brother’s name as Pappachan read the order. Two women sitting next to Juan in court tried to console him and hold him up as the hearing continued.

Bui, who is set to face charges for allegedly cold-cocking Jesus in front of a restaurant on a Fordham Manor street, has claimed to The Post in a jailhouse interview that he blacked out during the attack and shouldn’t be behind bars — because the victim survived.

“That s–t don’t make no sense,” Bui said. “He’s alive. He’s not dead. I thank God he survived. I didn’t want to hurt him that bad. I just hit him once.”

The suspect was allegedly caught on camera punching Cortes in the street and knocking him onto the concrete outside the Fuego Tipico Restaurant on East 188^th Street. Bui has told The Post that the pair had been arguing inside the eatery right before. It’s unclear what the alleged dispute was about.

Cortes was temporarily placed on a ventilator and put in a medically induced coma after the attack, which left him with a fractured skull, broken cheekbone and brain bleed.

In 1995, Phu was convicted of first-degree sex abuse involving a 17-year-old girl in The Bronx a year earlier. He was sentenced to six years to life in prison, according to state records.

He was paroled in 2019 and is now registered as a Level 3 sex offender — the most serious designation, records show.

His next hearing in the assault case is set for Sept. 15. If Bui is indicted on the felony charges, he will be arraigned on that date, prosecutors said.

Juan Cortes, prosecutors and Trimble declined comment after the proceeding.