The Supreme Court has today handed down judgement in Virgin v Zodiac. In a landmark decision, the Court reversed the previous and long-standing ‘Unilin’ principle which stated that a damages award, made after a finding of infringement of a patent, was unaffected by any subsequent decision revoking that patent (i.e. by the EPO, or by a later UK court) as a result of the res judicata rule. The Supreme Court held that the Court of Appeal decisions on which the previous principle was based were all wrongly decided. They considered that it was unjust to award damages on the basis of a patent which, given the retroactive nature of revocation, is now deemed never to have existed. Henceforth, a party found to infringe a patent will be able to rely on the fact that the infringed claims have since been revoked (or amended), in any subsequent enquiry as to damages.