LOS ANGELES >> Pop star Britney Spears has at last petitioned the court to appoint a successor to the conservatorship of her estate, calling her father’s broad control of her career and fortune “traumatizing, insane and depressing” in new legal documents filed today.

The documents, filed in Los Angeles Superior Court by the pop star’s newly appointed personal attorney — former federal prosecutor Mathew Rosengart — made good on his promise to move “aggressively and expeditiously” to relieve her father James “Jamie” Spears of his duties involving the 39-year-old singer’s life and finances. The petition asked the court to replace Jamie Spears with another fiduciary, interim conservator, certified public accountant Jason Rubin.

Earlier this month, Bessemer Trust, cited as co-conservator of Spears’ estate since November, resigned from the job it apparently never started.

The petition, obtained by the Los Angeles Times, described the relationship between Spears and her father as “venomous” and alleged that “it impairs Ms. Spears’s mental health, her well-being, and her ability to pursue and continue with her extraordinary career.”

It’s the latest in the hitmaker’s protracted court battle that has illuminated her fraught relationship with her father and conservatorship issues as a whole. Jamie Spears has been overseeing much of the singer’s personal and financial matters since early 2008, when the “…Baby One More Time” singer was put under court supervision amid a public meltdown. Her family has said it sought the conservatorship — known as a legal guardianship in other states — for the singer’s own protection. In most cases, conservatorships are used for the elderly and infirm.

Scrutiny of the arrangement has exploded in the past few years as the fan-fueled #FreeBritney movement gained steam and the FX/Hulu documentary “Framing Britney Spears” reinvigorated public interest. The arrangement came to a dramatic climax in late June when the singer addressed the court and essentially torched the state of the conservatorship and almost everyone involved in it.

In Monday’s petition, Rosengart argued repeatedly that the purpose of the conservatorship is to fight to protect the conservatee’s interests rather than gain control over the conservatee, which critics of the arrangement have long believed the elder Spears has done. Rosengart replaced court-appointed attorney Samuel Ingham III and the firm Loeb & Loeb, both of whom had recently tendered their resignations pending assignment of new representation.

Describing it as a “Kafkaesque nightmare,” Rosengart said that the conservatorship, at least when it comes to Jamie Spears, “has grown increasingly toxic and is simply no longer tenable.” The petition asks him to resign voluntarily or at least not oppose the petition for his removal.

Representatives for Jamie Spears’ attorney did not immediately respond to The Times’ request for comment Monday evening.

Rosengart also argued that Jamie Spears profited handsomely from his daughter’s conservatorship, noting that since at least 2009, he has been paying himself $16,000 per month from the singer estate, which is $2,000 more than he has allotted to his daughter. He also pays himself an additional $2,000 per month for office expenses. Rosengart also noted that the elder Spears is not a professional business or financial manager, and that the family has struggled financially under his leadership and filed for bankruptcy in 1998.

“(T)his Court is not, at this time, being asked to adjudicate wrongdoing on the part of Mr. Spears,” the documents said. “All Mr. Spears is being asked to recognize is that (i) his daughter’s best interests must be placed ahead of his own, (ii) whether he has done an exemplary job, failed as a fiduciary, or worse, his mere presence as conservator is detrimental to the well-being of a daughter, and (iii) accordingly, he should step aside in favor of a highly-respected fiduciary nominated by Ms. Spears. In any event and regardless of whether Mr. Spears resigns voluntarily (as he should do immediately), this Court should remove and replace Mr. Spears for these very reasons.”

Rosengart also has the backing of Jodi Montgomery, the conservator of Britney Spears’ person, and her mother, Lynne Spears.

The 20-page petition also said that Spears may have needed the legal arrangement when it was first initiated 13 years ago but that her circumstances have since changed.

Spears has described her relationship with her father as “traumatizing, insane, and depressing,” Rosengart argued, adding that the goal of the petition is to remove Mr. Spears as his daughter’s conservator and replace him with a “licensed professional fiduciary whose presence is not detrimental to Ms. Spears’s well-being.”

Rosengart reiterated that their father-daughter relationship is “so fractured” that she and her father “do not even speak” and that any interaction between the singer and her dad is “unwelcomed and needlessly stressful for Ms. Spears, who, … has testified that she is fearful of her father, along with many reasons for that fear.”

Monday’s hearing appeared to be set to finalize a request made by Montgomery to be compensated for her heightened security. Since the explosive June hearing, Montgomery said “the amount as well as the severity of the threats has drastically increased,” threatening her safety. (A July 19 hearing was held regarding the petition, but lawyers asked for more time to discuss Montgomery’s security issue.)

Montgomery has been conservator of Spears’ person since September 2019 and sees to her personal affairs. The temporary appointment has been extended through Oct. 8, according to a petition also filed today.

Jamie Spears refused to foot the bill for her security. In a response to her petition, Jamie Spears’ lawyers disagreed and objected to Montgomery’s request for 24/7 live security services for herself, which they said would cost the estate more than $50,000 per month for an indefinite period of time.

“Mr. Spears does not believe such an expense is reasonable, necessary, or a proper expense of the Conservatorship Estate,” the response said, adding that many people involved with the conservatorship, including Jamie Spears, have received similar threats but paying for similar security for each person is not sustainable. They also argued that Montgomery “should pay for any security services personally as a cost of doing business.”

“Mr. Spears, himself, has been the subject of innumerable and ongoing threats as well — not just recently, but for years,” the opposing document said. Britney Spears’ former court-appointed attorney Samuel Ingham III has also received threats, it says, and the estate wouldn’t be able to afford this kind of security for everyone involved, were they to request it.

Incidentally, because of a quirk in the the conservatorship system, Britney Spears is required to pay for lawyers on both sides, including those arguing against her in court.

A hearing scheduled Sept. 29 is supposed to deal with many of the accounting issues that have been delayed for months.

Earlier this month, Spears called for the immediate removal of her father from the conservatorship and accused him of conservatorship abuse, according to the Associated Press.

She also demanded that the protracted legal arrangement be terminated altogether, but not if it required going through more “stupid” evaluations questioning her intelligence. Spears described being denied things as basic as coffee, her driver’s license and her “hair vitamins” by the conservatorship.

Her father’s lawyer has said that he has “diligently and professionally carried out his duties” as one of his daughters conservators, and “his love for his daughter and dedication to protecting her is clearly apparent to the court.”

But the singer has reportedly pushed for her father’s removal for years, according to a report in the New York Times, which cited confidential court records and shed light on past closed-court proceedings from the pop star’s point of view — one that diverged from her rosy and sometimes inscrutable Instagram posts. For a time, those posts provided the only clue into her personal life under the conservatorship and, she admitted, often misled her fans.

Spears questioned her father’s fitness for his duties as early as 2014, in a hearing closed to the public, the newspaper said, and expressed serious opposition to the conservatorship earlier and more often than had previously been known.

“She articulated she feels the conservatorship has become an oppressive and controlling tool against her,” a court investigator wrote in a 2016 report, according to the newspaper.

Then, in the spring of 2019, Britney Spears appeared at a closed-door hearing and read a statement asserting that she had been forced into a mental health facility against her will on exaggerated grounds, which she viewed as punishment for standing up for herself and abruptly canceling her Las Vegas residency, the New York Times said.