AMP's legal battle with a former senior lawyer has turned ugly after the financial services giant filed a defence claiming she was not a team player, bad-mouthed the board and was subject to performance management over shortcomings.

The legal stoush began last week when Larissa Baker Cook lodged a $2.5 million damages claim against AMP claiming she was the senior lawyer who exposed the seriousness of the fees-for-no-services scandal.

Former senior AMP lawyer Larissa Baker Cook.

She alleged that shortly after her disclosure she was exposed to increasingly hostile and intimidating behaviour by some of her colleagues.

Ms Baker Cook was sacked in June after a confidential mediation failed. At the time she received a letter from AMP's lawyers saying the supporting documents provided in the mediation were legally privileged and that she was not authorised to use them. Ms Baker Cook claims she was allowed to use the documents and has launched a multimillion-dollar lawsuit for wrongful termination.