Britney Spears’ father and his law firm have hit back at her mother after she objected to the substantial attorney fees he requested Britney pays in her conservatorship case.

Britney Spears

Britney Spears

Last week, Lynne Spears filed court documents in which she challenged the fee of $890,000 for four months' work by her ex-husband's legal firm Holland & Knight, and branded much of the expenses "procedurally and substantively improper”.

And in a new court filing obtained by People magazine, Holland & Knight have now responded to Lynne’s request, calling it meritless and stating it holds "evidence bias”.

In the document – which seeks to have a judge overrule the objection – the law firm wrote: "Despite having zero involvement in her daughter's conservatorship until very recently, Lynne Spears is asserting claims as if she were a party directly involved in the litigation (which she is not).”

The firm also referred to Britney’s dad, Jamie Spears, as a “fiercely loving” father, and claimed Lynne is not "acting in the best interests" of Britney and that she has "no knowledge" about the fees related to the case, calling her claims that the firm acted improperly a "fictitious argument”.

The document continued: "Lynne Spears' math of dividing the total fees by four (to calculate fees per issue) is ridiculous and belies her ignorance regarding the complex nature of the Conservatorship Estate, and the issues that needed to be addressed by H&K to properly defend Mr. Spears from specious allegations that have threatened to tarnish his reputation as a loving, caring father who has nothing to hide, has been loyal and fiercely loving toward his daughter, sought to protect her, and manage her finances so that she can live her life the way she wants.”

In Lynne’s original filing, she argued the firm asked for compensation for work not "performed in good faith for the benefit" of her 39-year-old daughter, who has been under a conservatorship since her public breakdown in 2008.

The 'Toxic' hitmaker's mom also requested that $224,000 of the fees, which were used for press relations, be "immediately repaid" to Spears' estate, as it's "directly contrary to [Britney's] wish for privacy".

The document added how "unnecessary" work "largely constituted a 'national media tour' orchestrated by H&K to promote [Jamie's attorney] Ms. [Vivian Lee] Thoreen and/or to combat media coverage that cast Mr. Spears in a negative light”.

Lynne has also accused Holland & Knight of charging $200,000 more than "all of the other law firms combined, largely for similar work done”.