Britney, 38, whose situation has sparked the ongoing #FreeBritney fan movement, has refused to work again until her father's grip over her is loosened, Us Weekly reports.
A courtroom this week also heard the singer and her father no longer speak, and have no working relationship.
Samuel D Ingham, the lawyer representing the Toxic singer, referred to Britney as "a high functioning conservatee", and said she has told him on several occasions that "she is afraid of her father".
He added that Britney and Jamie having no "viable working relationship".
A representative for Lynne, who was present at the hearing on Tuesday, agreed that Jamie should be dismissed.
The lawyer stated that while Lynne wishes her ex-husband no ill will, his relationship with their daughter had deteriorated over the years and led to Britney having "dark days".
Her lawyer also alleged that Jamie said Britney is like a racehorse and needs to be handled as one.
Jamie's lawyer replied that it is all hearsay, adding that no one loves Britney more than her father.
The hearing comes a week after Britney took to Instagram to assure fans she is "fine" and "the happiest I've ever been in my life" amid the legal dispute and #FreeBritney movement.
"Hi, so I know that there have been a lot of comments and a lot of people saying a lot of different things about me. But I just want to let you guys know that I am fine," she said in a video.
She continued, "I'm the happiest I've ever been in my life and I'm sending all of you guys a lot of prayers and wishes and a lot of love."
The Womanizer singer has been the subject of several conspiracy theories during her conservatorship battle.
A #FreeBritney movement began after rumours swirled that the pop star was being held prisoner by her father, who has legally been her conservator for 12 years despite the fact she's been touring and making money.
Fans have even created a petition in hopes of helping the singer.
"Her father doesn't allow her to drive, all of her calls & messages are monitored, she's not allowed to vote, hang with anyone or spend her money without permission. And if she breaks a 'rule' he threatens to have her kids taken away," claims one Change.org petition, with more than 100,000 signatures, lobbying for Britney's freedom.
Jamie has slammed the movement and defended his role as Britney's conservator.
"All these conspiracy theorists don't know anything. The world don't have a clue," Jamie told Page Six in August. "It's up to the court of California to decide what's best for my daughter. It's no one else's business."
