Britney Spears is jumping the gun on making decisions about the future of her conservatorship … according to her father, who says the court first needs to make some other big decisions about Brit’s health.

Jamie Spears just filed new docs, obtained by 360APROKO, saying Britney’s lawyer is grandstanding by trying to unseal parts of her ongoing conservatorship case … opening it up to the public.

In the docs, Britney’s dad says before she can waive her right to privacy, the court needs to determine she has “the capacity to understand the consequences of her waiver.”

Jamie’s arguing for keeping her medical records sealed, and says he’s worried they could have a detrimental effect on Britney if the public gets their hands on them. He also says keeping that info sealed is in the best interest of Britney and her 2 children.

Britney’s dad also addresses her lawyer’s statement about Britney wanting more “personal autonomy” in her life, now that she’s not performing. In his docs, Jamie points out the conservatorship is voluntary, and Britney can file a request to terminate at any time — but has not up to this point.

As we reported … Britney says she doesn’t want her father to be the only one in charge of her financial decisions, and instead wants to add a co-conservator of her estate.

Jamie says the conservatorship of her estate (finances) is “inextricably entwined” with the conservatorship of her person (medical) … and argues that unsealing details of one could expose sensitive medical issues.