In Gibb v Maidstone & Tunbridge Wells NHS Trust, the Court of Appeal, overturning the previous High Court decision, held that the NHS Trust could not escape paying the sums due under the compromise agreement entered into with its previous Chief Executive as it had not acted ultra vires when entering into the agreement. The court made it clear that it will only be in very limited circumstances that a public authority can renege on its contractual commitments on the ground that it had acted ultra vires when entering into the contract.

The court also held that Ms Gibb would have had an alternative equitable claim for damages against the Trust on the basis that it had been unjustly enriched at her expense.