( CM ) - BRITNEY SPEARS' father JAMIE is furious at the amount of legal fees his daughter's custody fight with ex-husband KEVIN FEDERLINE has garnered - and is planning to contest the $1.1 million (GBP550,000) invoice at a court hearing next week (begs10Mar08). Jamie Spears was appointed conservator of the pop star's legal and financial affairs in February (08) and is in charge of her estate - with court-appointed observer Andrew Wallet - until 31 July (08), after he was granted an extension on Wednesday (05Mar08). But Jamie is reportedly disputing the high attorneys' fees he has been billed for - $500,000 (GBP250,000) from Federline's lawyer Mark Vincent Kaplan, and more than $600,000 (GBP300,000) from Britney's representatives Trope and Trope - for work carried out in the last five months, from October (07) to February (08). According to TMZ.com, Jamie has filed documents with Los Angeles Superior Court to challenge the invoice and a hearing is set to take place on Monday (10Mar08) - on the same day Spears is due to face her ex in a child custody/visitation case.