London, Dec 21 (ANI): Heather Mills is being sued by her former lawyers over her outstanding bills of 2million pounds relating to her bitter divorce battle with ex- husband Sir Paul McCartney - but she is determined to fight the 'extortionate' bill.

Celebrity firm Mishcon de Reya are set to issue the 39-year-old former model with the mega money writ for outstanding legal bills after her split from the former Beatle.

"She has been employing Mishcon for 20 months so it works out at 100,000 pounds a month," The Sun quoted Mills' pal, as saying.

"Did Mishcon need a team of six, each earning 500 pounds an hour, to fight her case?

"She says not, that she and her sister did a lot of groundwork," the pal added.

Howwever, a legal source said: "It was her choice to hire one of the country's most high-profile lawyers."

Mishcon de Reya dumped the animal rights activist after she embarked on a string of print and television interviews to rant about her divorce from the legendary singer. In case, the High Court writ is successful it could result in Mills being declared bankrupt.

Mishcon refused to comment on the matter. (ANI)