The Manhattan judge deciding the $250 million civil fraud case against Donald Trump muzzled and sharply rebuked the former president on Tuesday for a social media post in which he took aim at a court clerk and baselessly dubbed her “Schumer’s girlfriend.”

Manhattan Supreme Court Arthur Engoron, during the second day of trial, issued a limited gag order – and threatened “serious sanctions” if the directive is ignored.

“This morning, one of the defendants posted to a social media account a disparaging, untrue post about a member of my staff,” Engoron said in court after an extended lunch break.

The missive in question was posted by Trump, 77, shortly before noon Tuesday on Truth Social and included a picture of Engoron’s longtime law clerk standing with Senate Majority Leader Chuck Schumer (D-NY) at a campaign event.

“Schumer’s girlfriend, Allison R. Greenfield, is running this case against me,” Trump wrote without evidence in a caption that linked to her Instagram account.

“How disgraceful! This case should be dismissed immediately!!” he added.

A Schumer spokeswoman Tuesday called Trump’s post “ridiculous, absurd, and false,” saying that the senator does not know Greenfield.

“As is well known, Sen. Schumer attends countless events in every corner of the state where tens of thousands of constituents take photos with him, just like this one, which was taken at a stop at an annual brunch in Manhattan,” the statement said.

Trump also separately said Monday that Greenfield “should not be allowed to be in his ear on every single question” and claimed she “hates Trump.”

The post was removed during the court’s lunch break later in the day – after Engoron said he ordered it be taken down – but was sent out via email by Trump’s 2024 campaign.

“Although I have since ordered the post to be deleted, it has been mailed out to millions of others,” the judge said.

“Consider this a gag order,” Engoron said, elaborating that the ruling relates to all parties in the case and covers verbal attacks on court staff.

“Personal attacks of my staff are inappropriate and I won’t tolerate them,” he said.

Engoron made the statements after a roughly 45-minute long closed-door meeting in the court, where media were not allowed inside.

“Yesterday, I warned counsel of this and it was disregarded,” he said. “Failure to abide by this directive will result in serious sanctions – I will be very clear.”

He didn’t elaborate further on what the sanctions would be.

Greenfield is an experienced clerk who has been with the judge for several years, according to a real estate attorney who has argued more than 100 cases before Engoron.

Engoron is known to involve his law clerks more than the typical judge does, and it’s common for him to huddle with them during a proceeding for a side conference. 

Sometimes they even participate in oral arguments, asking questions of the attorneys on the judge’s behalf, said real estate attorney Adam Leitman Bailey, who has also taken the Trump Organization to court in the past, to The Post.

This means that what Trump has observed at his civil fraud trial is routine practice for Engoron and not targeted treatment.

The former president voluntarily attended the first and second day of trial in the New York Attorney General Letitia James’ lawsuit in which she claims Trump exaggerated his wealth on Trump Org financial documents from 2011 through 2021.

The former president has taken every opportunity in the presence of the press and on social media to blast the black AG as a “racist,” calling her case a sham and saying the judge is on a witch hunt against him.

In Manhattan District Attorney Alvin Bragg’s criminal “hush money” case against Trump — which is pending trial next year — Justice Juan Merchan also issued a limited gag order barring Trump from publicly discussing evidence.

Over the first two days of the ongoing trial — which is expected to last through December — prosecutors in James’ office claimed that Trump inflated his net worth for vanity’s sake so he could climb the Forbes’ list of billionaires and save hundreds of millions on loans and insurance.

The AG’s Office played clips of former Trump “fixer” Michael Cohen’s deposition tapes in which he claimed his one-time boss ordered him to pump up his assets to inflate his overall worth.

Meanwhile, Trump’s side argued that the AG’s case hinges, in part, on the word of Cohen, a convicted felon and liar.

The first witness in the case, Donald Bender — a partner at accounting firm Mazars USA — has been on the witness stand through Tuesday testifying about his time working the Trump account.

On Monday, Bender testified that he’d noticed that there was a discrepancy in the valuation of Ivanka Trump’s Park Avenue penthouse on Trump’s financial statements versus the price that the daughter could have bought the unit for.

The AG has alleged that while the company listed the posh pad’s worth at over $20 million, Ivanka’s rental lease had a buy option price of just $8.5 million — another example of exaggerating his assets.

Trump’s team didn’t immediately return a request for comment on the gag order Tuesday.

Trump did not comment on the order as he left court, vowing only that he’d be back Wednesday.

“I’ll be back tomorrow. Good day — it’s been a very good day,” he told reporters.

With Post wires