McCartney, 63, and former model Mills, 38, announced their separation on Wednesday, blaming media intrusion for the collapse of one of the most high profile show business marriages. Lawyers believe the divorce would not degenerate into a messy court case but they said McCartneys decision not to seal a pre-nuptial deal could cost him dear in a private settlement.
The couple, who have a two-year-old daughter, Beatrice, met in 1999 at a charity event, a year after McCartneys first wife died of breast cancer. Lawyer Mark Stephens of Finers, Stephens and Innocent told Reuters: Heather and the child need to be looked after financially. I think you are looking at 150 million to 200 million pounds. She is the child of a Beatle and they have to live in a cosseted and protected environment, he said.