Britney Spears' new lawyer, Mathew Rosengart, is wasting no time as he joins the pop star’s ongoing conservatorship battle.

Speaking to reporters on Monday, Rosengart — whose firm has represented celebrities includingSteven Spielberg,Sean Penn,Ben AffleckandEddie Vedder— said that he is working “aggressively” and “expeditiously” to remove Britney’s father Jamie Spears from her conservatorship.

“First, I once again want to thank Britney Spears forher courage and for her strength,” Rosengart said invideo footage shared on Twitter. “I want to thank Judge [Brenda] Penny for her courtesy welcoming my firm and I into this case. And I also want to thank Britney Spears' fans and supporters. The outreach and support for my firm, myself, and most importantly, Britney, has truly been overwhelming.”

“Finally, and the last thing I’m going to say about this matter, is as I said in court last week, and outside,my firm and Iare moving aggressively and expeditiously to file a petition to remove Jamie Spears unless he resigns first.”

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Britney’s “main goal” after hiring Rosengart, a source told PEOPLE last week, is to see her father Jamie removed as the conservator of her estate.

“She’s reallyhappy and excitedthat she has new representation,” the source said. “She feels like she’s finally heading towards ending this.”

Rosengart is also expected to ask the court toforgo a mental health evaluationfor Britney, who “doesn’t have much trust for the doctors that she has worked with so far,” a source told PEOPLE earlier this month.

Jamie, 69,stepped down as his daughter’s personal conservatorin late 2019, but remains in charge of Britney’s finances afterfiduciary company Bessemer Trust resigned as co-conservator of her estate.

Britney Spears.getty

Britney Spears

Britney spoke publicly about the 13-year conservatorship for the first time in animpassioned speech to the court on June 23. The singer’s personal conservator Jodi Montgomery and Jamie have been sparring publicly in the weeks since.

Britney reportedly told Judge Penny in court last week that she is “extremely scared” of Jamie. “This conservatorship has allowed my dad to ruin my life,” she said, NBC News reported. The outlet added she said she wants to charge her dad with “conservatorship abuse.”

source: people.com