It’s a Jackson family battle of wills.

In a legal showdown, the late Michael Jackson’s youngest son, Bigi, has unleashed a legal challenge against his grandmother, Katherine Jackson.

Court briefs filed by Bigi, formerly known as Blanket, show that the 93-year-old matriarch is trying to tap into funds from Michael’s estate to challenge a $600 million music catalog deal.

Katherine’s side argues that the estate should cover her $500,000 legal fees, while Bigi disagrees.

“… it seems clear to [Katherine] that the Executors are holding all of the assets in the Estate in order to keep control over them, and to avoid the more liberal distribution requirements of the Trust,” says a new complaint filed by Katherine’s attorney, according to People.

Katherine Jackson, seen here with son Michael Jackson in 2005, argues that his estate should cover her $500,000 legal fees in a dispute. WireImage© Provided by New York Post

But close family sources say this is not really about Bigi, now 22, trying to deny his grandmother anything.

Rather, it’s about trying to wean the extended family off Michael’s legacy.

“Bigi isn’t going against his grandmother. Bigi is really trying to protect his grandmother in the same manner that Michael did, which is to protect her from the Jacksons!” a longtime family associate told The Post.

“It’s the same s–t,” the associate said, alleging that some relatives get money from the trust via soft-hearted Katherine. “Now, instead of letting Mrs. Jackson live out her years in relative peace, you still have certain family members using this elderly woman to get more money — and it’s none of their business, as usual.”

Sources say Bigi — formerly known as Blanket seen here in 2022 — is actually trying to protect his grandmother. Getty Images© Provided by New York Post

Sources say that Katherine — seen here in 2013 with Michael’s son Prince Michael, who supports Bigi’s actions — is too soft-hearted when it comes to giving other family members money. Getty Images for Cirque du Soleil© Provided by New York Post

“Through Katie, the estate has made everyone wealthy beyond their wildest dreams,” one Jackson insider said.

Katherine is not a beneficiary of her late son’s main estate, but of a separate trust.

Nearly 15 years after his death, Michael’s fortune has undergone a miraculous transformation, thanks to the stewardship of lawyers John Branca and John McClain, who are the executors of his estate — bringing it from an estimated half-billion dollars debt to a multi-billion-dollar empire.

Branca and McClain have accomplished this feat through shrewd management — including launching the Tony-nominated “MJ The Musical” — and a determination to keep Michael’s extended family at arm’s length.

Bigi, seen here in Michael’s arms, was only 7 years old when his father died. His brother, Prince Michael, was 12 and sister Paris was 11.© Provided by New York Post

“Exercising the powers granted in Michael’s will as confirmed by the probate court, [executors] entered into business transactions involving the estate’s assets that skyrocketed the estate’s value to over $2 billion,” lawyers wrote in an appellate brief this month, acknowledging that the “Thriller” singer was near bankruptcy when he died.

But behind the veneer of prosperity lies a family torn apart by greed, ambition and envy.

Bigi’s now public disagreement — family sources vehemently object to any characterizations that it’s a feud — with his grandmother has opened past wounds and ignited tensions within the Jackson clan.

Meanwhile, sources say the estate worries such in-fighting could threaten years of painstaking and successful effort to rebuild Michael’s reputation and keep cash flowing into the pockets of the legendary moonwalker’s heirs.

“Fair warning: Keep bad mouthing and throwing low blows at my 93-year-old grandma and my gloves will come off,” Tito Jackson’s son, Taj, tweeted last week.

While Bigi keeps a low profile, he did speak to “Good Morning Britain” in 2021, advocating for world leaders to do more about climate change. Good Morning Britain© Provided by New York Post

But insiders told The Post that Taj and other family members misunderstood Bigi’s argument that the estate should no longer foot his grandmother’s legal bills.

They also believe an unidentified faction of the family is pushing Katherine to fight the estate, but made clear that Bigi’s siblings — Prince Michael, 27, and Paris, 25 — are in support of their brother’s court fight.

“Bigi simply said he believes it’s a waste of money. He’s being financially responsible based on his belief that the court will rule against Katie and lawyers will charge her a premium,” the Jackson insider said, using the family nickname for Michael’s mother.

“It’s not Katie [fighting for the money], although her name is on the documents. Katie is 93 years old and long ago gave up any real fight against the estate,” the Jackson insider added. “But some members of the family haven’t given up going against [Branca and McClain] even though Katie still takes great care of the entire family through money that comes in from the estate. But you got this faction that, after 15 years, that’s still angry because a family member isn’t calling the shots.”

Sources told The Post that Bigi’s (front row) siblings, Prince Michael and Paris, support his legal fight. They’re seen here with grandmother Katherine and aunt Latoya Jackson in 2011. Getty Images© Provided by New York Post

The Post reached out to attorneys for Bigi and Katherine Jackson, as well as to the Michael Jackson estate.

Asked whether there was a consensus on who should control Michael’s money, the Jackson insider laughed: “When has there ever been a consensus around here?”

Katherine and Bigi initially were united in an attempt to stop Branca and McClain from completing an estimated $600 million deal with Sony Music; the deal, which closed late last year, gave the company 50% control of Michael’s publishing and recorded masters catalog.

Katherine believes the estate should have waited and netted more cash while the executors argued they took advantage of a white-hot market that could implode in the future. They also noted that, unlike with many other catalog deals, Michael’s heirs remain in control of his music.

Bigi reached notoriety at eight months old when his father dangled him over the balcony of a Berlin hotel in 2002. Getty Images© Provided by New York Post

Michael Jackson affectionately referred to his youngest son, seen here in 2012, at age 10, as “Blanket.” FilmMagic© Provided by New York Post

Earlier this month, a California judge sided with the executors and allowed completion of the transaction.

Now, Katherine wants to appeal the judge’s decision while Bigi is adamantly opposed. A hearing is scheduled in May to determine whether a judge will order the estate to pay Katherine’s legal tab, currently estimated at around $500,000. Bigi believes it’s a losing proposition and that his late father’s money could be better spent elsewhere.

“Bigi decided not to waste his resources to participate in an appeal,” his attorneys wrote in court filings. “Nonetheless, Katherine has decided to appeal this court ruling. That decision is not for the benefit of the heirs.”

Endeavors like the Tony-nominated “MJ The Musical” have boosted Michael Jackson’s estate to a multi-billion dollar fortune. Getty Images© Provided by New York Post

Myles Frost won raves for portraying Michael Jackson in “MJ The Musical” AP© Provided by New York Post

The court battle has, at times, gotten testy, with estate lawyers pointing out that Katherine has received more than $55 million as a trustee — including the estate paying her personal and property taxes, providing her with 24-hour security and a personal chef, and other benefits.

“Virtually no request of Mrs. Jackson for her care or maintenance has been declined,” estate lawyers argued.

But Katherine’s attorney, Adam Pines, has countered that “ … when they say, ‘Oh, we can’t pay this, our hands are tied, and the procedural requirements have not been met,’ I don’t think it’s fair.”

The Jackson insider said that Bigi and other family members who side with him have commended Branca and McClain for keeping “their eyes on the prize” despite a devastating 2019 documentary that dredged up old allegations against Michael.

Lawyer John Branca is one of two executors of Michael Jackson’s estate. Getty Images© Provided by New York Post

The superstar had long been dogged by child sexual abuse allegations and paid out millions to settle claims against him despite being acquitted of 13 charges.

“Consider that people like R. Kelly and Bill Cosby have actually gone to prison, and then the ridiculous documentary about Michael, yet [the executors] have been able to plow through and restore Michael’s good name, and everyone, young and old, celebrates him,” the insider said.

The longtime associate added that Katherine’s relationship with Bigi remains nurturing and supportive and said the matriarch maintains a healthy and loving bond with him and his siblings: “They are Michael’s kids, which means they are highly favored and cherished by Katie.”