PAUL and Heather Mills McCartney have raised the stakes in their increasingly acrimonious divorce battle, hiring the same two lawyers who represented Prince Charles and Princess Diana when they split in 1996. Mills, who married the former Beatle in 2002 and had a daughter, Beatrice, with him, has named Anthony Julius of leading law firm Mishcon de Reya to fight her side. Julius represented Diana in the divorce case. "Yes. It was decided today," said Mills' spokesman Phil Hall today, when asked to confirm Julius' appointment. It has already been widely reported that McCartney had hired Fiona Shackleton, who acted for Prince Charles against Diana, to argue his case. Prince Charles married Lady Diana Spencer in 1981, but the marriage collapsed amid mutual accusations of adultery.