The Court of Appeal has condemned a Surrey law firm and one of its former solicitors over the intransigent conduct of litigation between the two.

Croydon-based McMillan Williams is suing one-time family law assistant Sarah Range for 18,333 it says she owes under an employment contract which saw Ms Range paid a salary only as an advance on commission from profit costs she generated.

Ruling on a preliminary issue, Lord Justice Ward was scathing in his criticism of their approach to the litigation - which has so far cost 50,000 - and unwillingness to resolve it through mediation, from which the firm had withdrawn.

'My attitude is best summed up as "a plague on both your houses", 'he said.

He added: 'This is a case where we should condemn the posturing and jockeying for position taken by each side of this dispute and thus direct that each side pay its own costs of their frolic in the Court of Appeal.'

Ms Range joined the firm in April 1999 on a 33% commission, rising to 50% for billings over 130,000, and received a monthly advance on it equivalent to 22,000 a year.

However, the work was apparently largely legally aided, and Ms Range billed 'significantly less' than the 66,000 needed to cover the monthly payments.

She resigned in November 2000.

The firm then issued a claim for a 17,000 shortfall on the arrangement plus interest.

In her defence and counterclaim, Ms Range alleged that McMillan Williams had negligently misrepresented the volume and quality of work in the family department.

She also claimed that the contract made advances to her against future commissions, meaning it was a regulated agreement under the Consumer Credit Act 1974.

If so, it was not executed properly and thus unenforceable.

The court at first instance upheld this defence, but it was overturned by the Court of Appeal.

McMillan Williams is represented by Martin Cray of Brighton firm Martin Cray & Co, who declined to comment on the ruling.

Camilla Dorling, an associate at Brighton firm DMH acting for Ms Range, said her client was disappointed that the case had even been issued.

'She worked hard for the firm in a difficult legal market,' she said.

While not disagreeing with the court's observations about the costs, Ms Dorling said Ms Range had had no option but to defend herself, pointing out that it had been McMillan Williams which withdrew from the mediation.

Neil Rose