A Family Court judge has delivered a blistering judgment on the "culture of bitter, adversarial and highly aggressive family law litigation" in Sydney and blasted two law firms for charging "outrageous" fees.

In a judgment published on Wednesday, Justice Robert Benjamin said he regularly heard cases filed in the Sydney registry of the Family Court and was "increasingly concerned about the high levels of costs charged by the legal profession in property and parenting proceedings".

Family Court Justice Robert Benjamin said solicitors are "not employed to act as 'postman' to vent the anger and vitriol of their clients". Credit:Karl Hilzinger

He asked the Legal Services Commissioner to investigate whether the fees charged by the solicitors acting for a former couple fighting over parenting arrangements and property could constitute professional misconduct.

Justice Benjamin said the couple, given the pseudonyms Mr Simic and Ms Norton, had spent an "eye-watering" $860,000 in the proceedings and "these amounts are, on their face, outrageous levels of costs for ordinary people involved in family law proceedings".