"Ms Spears' emotional health and wellbeing must be, and are, the paramount concern," Britney's defence claimed.
"Further, all interested parties forcefully agree that Mr Spears' continued presence as Conservator of the Estate is contrary to Ms Spears' best interests, health, and wellbeing, and that his prompt removal — or, at the very least, his immediate suspension — is 'critical' at this juncture."
After the plea was denied, Britney, 39, took to Instagram to declare she felt "completely hopeless" and that she would post less on social media for the time being.
She also posted a video of a fan flying a "#FreeBritney" flag, saying "one day I will love on the edge !!!! One day ..."
"In a system where I've felt completely hopeless for so long, at least I do have a platform to share. The world can be a nasty place ... I know it ... you know it ... kill them with kindness.
"Unfortunately the news has been pretty nasty, saying horrible and mean lies about me so I'm gonna post a little less from now on. TA TA."
It comes after Jamie Spears alleged in court documents that Britney's personal conservator, Jodi Montgomery, frantically called him on July 9 to communicate her alleged fears about the pop star's mental health.
"Mr Spears received a call from Ms Montgomery on July 9, 2021, in which she sounded very distraught, expressed concern about Ms Spears' recent behaviour and her refusal to listen to or even see her doctors," lawyers for Jamie Spears claimed in the filing obtained by Fox News.
Jamie Spears alleged that Montgomery "pleaded for Mr Spears' help to address these issues".
The filing went on to state that his "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".
The filing alleges that Jamie Spears believes his daughter's alleged medical treatment is "indeed serious".
In a statement obtained People, Montgomery refuted Jamie Spears' claims, saying the phone call was being "misrepresented and manipulated".
According to Jamie Spears, he told Montgomery he was no longer privy to Britney's medical information and wasn't able to help, which according to him led Montgomery to question if putting Britney under a 5150 psychiatric hold would be the best option.
In response, Montgomery said she "at no time … express[ed] to Mr Spears that Ms Spears would currently qualify for such a hold".
