Britney Spears' lawyer is calling her father's decision to petition to end her conservatorship a "massive legal victory."

In a statement obtained by PEOPLE on Tuesday, Mathew Rosengart said that Jamie Spears' filing also represents "vindication."

"Having exposed his misconduct and improper plan to hold his daughter hostage by trying to extract a multi-million dollar settlement, Mr. Spears has now effectively surrendered. There is no settlement," Rosengart said.

"To the extent Mr. Spears believes he can try to avoid accountability and justice, including sitting for a sworn deposition and answering other discovery under oath, he is incorrect and our investigation into financial mismanagement and other issues will continue," the attorney added.

On Tuesday, Jamie, 69, filed to end his daughter's conservatorship after 13 years.

While he stepped down as the conservator of her person in late 2019, Jamie has remained in charge of the 39-year-old's finances as a conservator of her estate. He told the court last month that he'd step away only "when the time is right."

And while the filing defends the initial establishment of a conservatorship, it also indicates that Jamie believes Britney is "entitled to have this court now seriously consider whether this conservatorship is no longer required."

"As Mr. Spears has said again and again, all he wants is what is best for his daughter," the filing says. "If Ms. Spears wants to terminate the conservatorship and believes that she can handle her own life, Mr. Spears believes that she should get that chance."

Britney spoke out against her conservatorship publicly for the first time over the summer. At two hearings in June and July, she accused her father of what she called conservatorship abuse, and said that she just wanted her "life back."

As recently as Aug. 12, Jamie slammed the "unjustified attacks" against him in a filing after Rosengart filed a motion to remove him from his role and replace him with a CPA.

"It is highly debatable whether a change in conservator at this time would be in Ms. Spears' best interests," Jamie's August filing stated.

"Mr. Spears is willing to step down when the time is right, but the transition needs to be orderly and include a resolution of matters pending before the Court," the documents said. "In order to reach that result, the Court should encourage all interested parties to meet and confer in order to resolve those pending matters in the best interests of Ms. Spears."

Jamie said that his voluntary resignation would be contingent upon approval of his latest accounting (including $1.4 million in attorneys' fees he incurred over the span of a year) and a substantial payment from Britney's Estate to certain third parties, including Tri-Star Sports & Entertainment Group.

At the time, Rosengart told PEOPLE that his requests were "inappropriate and unacceptable."

Though Jamie said in his response that there were "no urgent circumstances" regarding his immediate suspension, Rosengart argued that "is false."

"The world heard Ms. Spears's courageous and compelling testimony," he said, referencing the singer's emotional June 23 testimony. "Britney Spears's life matters. Her well-being matters. Every day matters. There is no basis to wait."

After that testimony, Jamie's attorney Vivian Lee Thoreen told the court Jamie was "sorry" to see his daughter in pain. And in a recent filing, Thoreen insisted Jamie's "sole motivation has been his unconditional love for his daughter and a fierce desire to protect her from those trying to take advantage of her."