The real issue would not be whether the KFG companies can use the rule in Abouloff v Oppenheimer & Co in aid of a positive claim, but rather whether, where a foreign judgment is relied on by way of defence, that defence may be defeated by the claimant establishing that the judgment in question is impeachable on any of the c grounds available at common law. There is no reason in principle why it should not be possible to adduce fraud in opposition to a defendant’s reliance on a foreign judgment