Former Harper’s editor Ellen Rosenbush is back at the monthly as interim editor — even as the latest blowup between fired Editor-in-Chief James Marcus and Publisher John “Rick” MacArthur grows nastier by the day.

“Editorial Director Ellen Rosenbush is back in charge for the time being,” said Harper’s VP of communications, Giulia Melucci.

Rosenbush was boss from 2010 to 2015, when she was replaced by Christopher Cox — who only lasted three months before getting bounced in early 2016, ushering in Rosenbush’s return as interim editor.

That lasted a few weeks — until Marcus was tapped for the top job that March.

The public spat between Marcus and MacArthur first broke into the open on Monday when Publishers Lunch, an insiders newsletter, revealed that Marcus was fired last Friday.

The ousted editor told the newsletter it was his role opposing Katie Roiphe’s controversial March cover story, “The Other Whisper Network: How Twitter Feminism Is Bad for Women,” that triggered his exit.

The article, you remember, stirred up a hornet’s nest of controversy among feminists even before it hit newsstands over whether it planned to publicly name the originator of the S–ty Media Men list.

The list detailed alleged offenses by prominent men in media — from lewd and inappropriate comments to attempted rape — and ID’d the alleged perpetrators by name and company.

More than 100 names were on the list, which had first been getting quietly circulated just as the #MeToo movement gathered momentum.

Roiphe found the list’s author, Moira Donegan, who chose to “out” herself in advance of the article after Harper’s fact checkers contacted her. Feminists blasted Roiphe on Twitter at the time for her role in outing the list’s creator.

Now, a month after the cover story hit, Marcus revealed it was his undoing.

“All I can say for the moment is that Katie Roiphe’s article was assigned over my objections by Rick MacArthur, the magazine’s publisher,” Marcus told the newsletter. “I nonetheless worked very hard on the piece, as did the rest of the editorial staff.

“I had hoped that despite our differences, Rick and I could agree to disagree and move on,” Marcus said. “He could not. When I was fired on Friday afternoon, it was clear that the dispute over Roiphe’s article was the main cause.”

But that’s not what Harper’s is saying.

“The idea that James Marcus was fired over the Katie Roiphe story has little in common with the truth,” said Melucci, who claims it was she who had assigned the story — and MacArthur who backed her.

“That is one small part of a larger and more complicated story,” Melucci said in returning fire. “We’re amused at how he is trying to position himself as a martyr for the #MeToo movement.

“If he had truly taken a stand, he would have quit over the piece. Instead, he tried to undermine it and then, when he was fired months later, claimed that it was over some noble stand he took.”

Marcus disputes that Melucci had “assigned” the story. “By herself, she didn’t have the authority to assign or edit anything: She’s a publicist. So it was Rick’s call.”

Rosenbush first served as interim editor in 2010 when “sexy cowboy” Editor-in-Chief Roger Hodge was fired after a four-year run. She ended up holding down the fort for five years.

This time, Harper’s is insisting she’ll be a short-timer. “A replacement will be named in due course,” said Melucci.