Last week Mr Justice Langley struck out a major part of the near £90m claim, giving Moore Stephens the right to appeal against the rest of the suit.

A source at Moore Stephens said that the firm would be ‘vigorously defending the claim’ but hoped to get the rest of the audit negligence suit, brought by the liquidators of defunct agricultural company Stone & Rolls, struck out.

Moore Stephens must file a notice of appeal at the Court of Appeal by the end of September, after which prosecution lawyers Norton Rose will have a month to reply.

The firm is gearing up for the appeal to go ahead in the ‘first quarter of the year’, it said.

Last week Moore Stephens was boosted by Mr Justice Langley’s strike-out of a compound interest claim £40.5m ($81m), which made up nearly half of the £85.3m suit: ‘In my judgment the compound interest claim is hopeless,’ he said.

The case is thought to be the first of its kind to be bankrolled by litigation funding, a practice widely used in the US and Australia.

Debate has raged on the legitimacy of a third party with no connection to the plaintiffs funding the claim in return for a slice of the damages. Concerns have been raised that if Moore Stephens were to lose, it could pave the way for a flurry of similar claims.