Britney Spears has said in a court filing that she agrees with her father that the conservatorship that has controlled her life and money since 2008 should be terminated.

The filing in Los Angeles Superior Court from Spears’ lawyer Mathew Rosengart says she “fully consents” to “expeditiously” ending the conservatorship, which her father James Spears, who has controlled it for most of its 13 years, asked for in a petition on September 7.

It is the first time Britney Spears has called for an end to the arrangement in court documents, though she has called for its termination in hearings.

Her filing emphasises, however, that it is more important to her that her father be removed, calling it “a necessary first – and substantial – step towards Ms Spears’s freedom and ending the Kafkaesque nightmare imposed upon her by her father, so that her dignity and basic liberties can be restored”.

It is urgent that James Spears be suspended from his role of conservator of Britney Spears’ finances by September 29, the next hearing date in the case, the filing says.

“Mr Spears cannot be permitted to hold a position of control over his daughter for another day,” the document says.

The documents also disclose that Britney Spears is in the process of putting together a pre-nuptial agreement after becoming engaged to her longtime boyfriend Sam Asghari earlier this month.

That process will mean the intensive involvement of the conservator of her money, a role her father cannot be permitted to play, the filing says.

The flurry of major filings means that next week’s hearing could be pivotal.

Judge Brenda Penny, who has remained largely neutral in her oversight of the case, will be pressed to decide whether to remove James Spears or to put the conservatorship on a path to termination.

James Spears stepped aside as conservator of his daughter’s person in 2019, maintaining only his role as conservator of her money.

He and his layers have said that renders many of his daughter’s complaints about his control meaningless.

Jodi Montgomery, a court-appointed professional, now acts as conservator of Britney Spears’ person. Wednesday’s filing from Britney Spears says Montgomery also consents to ending the conservatorship,

Spears had said in a dramatic June 23 speech in court that gave a jolt to the case and galvanised support for her that she was being compelled under the conservatorship to take certain medications and to use an intrauterine device for birth control against her will.

James Spears has denied acting in anything but his daughter’s best interest, and has rejected demands that he resign immediately, though he said in court documents that he does have a plan to eventually step down.

But in a major reversal and possibly strategic move, he said in his September 7 filing that if she “wants to terminate the conservatorship and believes that she can handle her own life, Mr Spears believes that she should get that chance”.

Rosengart has sought to keep the focus on James Spears removal since his hiring in July, and says he will pursue an investigation of his handling of the conservatorship even after any removal.

The conservatorship was established in 2008 when Britney Spears began to have very public mental struggles as media outlets obsessed over each moment, hordes of paparazzi aggressively followed her everywhere, and she lost custody of her children.