Britney Spears' new attorney Mathew Rosengart has had another busy day in court amid the pop star's conservatorship battle as the court date to address the star's latest request -- that her father Jamie be removed as conservator – was moved up.

Fox News confirmed on Monday that Rosengart filed to have someone else oversee Spears' estate instead of the singer's father, Jamie, asking that he be replaced with Jason Rubin. Rosengart called the move an "objectively intelligent preference to nominate a highly qualified, professional fiduciary in this circumstance."

Also during the hearing, all parties continued to work on an agreement to pay for Jodi Montgomery's security and agreed to cap the cost at $50,000, though they did not officially reach an official agreement.

Vivian Thoreen, the attorney for Spears' father Jamie, who previously balked at the $50,000 request, said that as long as the singer consents, her client now approves of the number.

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The security costs will be re-evaluated in the September hearing alongside Spears' request to remove her father as conservator.

Britney Spears attends the MTV Video Music Awards in 2016.

Britney Spears' attorney Mathew Rosengart has officially filed to remove her father Jamie as her conservator. (Photo by Nicholas Hunt/FilmMagic)

Rosengart spoke to the press outside of the courthouse as he has done in the past.

"I once again want to thank Britney Spears for her courage and her fortitude," he said. "I want to thank her fans who have been incredibly supportive of her on social media and otherwise throughout the country and throughout the world and she deserves it and she appreciates it."

He continued: "Finally in terms of substance, I will be very brief. Less than two weeks ago, we pledged that after 13 years of the status quo, my firm and I would move aggressively and expeditiously to file a petition to suspend and remove James P. Spears [as conservator]. It is now a matter of public record and I announced to judge Penny this afternoon that we have done so in less than two weeks we look forward to litigating the matter in court, thank you very much."

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Finally, the hearing also addressed Montgomery's temporary position as Spears' conservator of person and extended her time in the position until October 8.

Monday saw several shifts in the conservatorship as well, as Bessemer Trust's request to be removed from the case as conservator of Spears' estate was approved by Judge Penny.

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The company was originally set to serve as co-conservator alongside Jamie, 69, but requested to be left out of the situation after the "Toxic" singer's bombshell testimony in June, in which she made several serious allegations against her father and the conservatorship as a whole.

Jamie Spears currently serves as Britney Spears' conservator. (AP Photo)

Jamie Spears currently serves as Britney Spears' conservator. (AP Photo)

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At the time, Spears, 39, said that she was barred from various activities, including riding in the car while her boyfriend Sam Asghari drove. She also claimed that despite wanting to have a third child, she is not allowed to remove contraception from her body and even compared her treatment to a form of sex trafficking.