Mick Mulvaney didn’t jump from his position as acting White House chief of staff — he was pushed, after falling out of favor with President Trump, insiders tell The Post.

“Mick was basically a pariah in the building,” a source close to the president said.

In a tweet fired off after he landed in Florida for a weekend at Mar-a-Lago, Trump announced Friday night that North Carolina Rep. Mark Meadows will be his new chief of staff and that Mulvaney would be the US special envoy for Northern Ireland.

Mulvaney, who had been acting chief of staff for more than a year, will also be stepping down as budget director.

He was ousted after “worsening relations as of late, to the point where Trump stopped including him in major meetings,” said the source.

Trump tellingly ignored Mulvaney on Air Force One during a March 2 flight to a North Carolina rally — instead chatting throughout the trip with Meadows, the source noted.

“Meadows is a calming influence. He’s a little closer to Trump’s age,” the source said and is part of the conservative Freedom Caucus.

Mulvaney’s own chief of staff, Emma Doyle, had meanwhile become “the bane of Trump’s existence,” the source said.

“She was blocking people and making staffing decisions,” the source said.

She was also “busting Johnny McEntee’s balls,” the source said.

However, a different source was unaware of any tension and countered that Doyle had actually been instrumental in McEntee’s return to the White House.

McEntee is Trump’s controversial new chief of presidential personnel, responsible for all White House firing and hiring. He had served as Trump’s “body man” until he was fired over security clearance concerns two years ago.

Trump had booted Mulvaney from the White House at least once before — in June, for coughing during the president’s interview with ABC News anchor George Stephanopoulos.

“If you’re going to cough, please leave the room,” Trump chided him in a caught-on-camera scolding. “You just can’t, you just can’t cough. Boy oh boy. Okay, do you want to do that a little differently … ”

As recently as last month, though, Trump had shot down a report that Mulvaney was leaving the White House.

But while Mulvaney’s ouster was rumored for months, the Friday night tweet came as a surprise to many White House aides.

The move makes Meadows, who announced he was not seeking reelection for his House seat from North Carolina, effectively Trump’s fourth chief of staff since taking office in 2017.

OMB acting director Russ Vought will likely be nominated to take the budget helm full time, a White House source told The Post.