THE AVAILABLE DEFENCES FOR RESTITUTION FOR WRONGS
Where the claimant seeks restitution from the defendant in circumstances in which the defendant has committed a wrong, the question of which defences are available to the defendant is a matter of some complexity, depending on the nature of the restitutionary claim. There are three fundamental principles which need to be borne in mind when determining what defences are available to the defendant.
(A) RESTITUTIONARY CLAIM FOUNDED ON THE DEFENDANT’S WRONGDOING
Where the restitutionary claim is founded on the commission of a wrong by the defendant, any defence which applies to the wrong should also apply to the restitutionary claim. If the effect of the defence is to extinguish the cause of action then there can be no wrong on which the claim can be based. For example, as regards limitation periods, the relevant limitation period should be that which relates to the particular wrong rather than to a cause of action founded on unjust enrichment. Similarly, when tortious causes of action were defeated by the actio personalis bar, by virtue of which the personal representatives of a deceased wrongdoer could not be liable for a wrong committed by the deceased, this bar would defeat the claim even where the claimant sought restitutionary relief.
-  Beaman v ARTS Ltd  2 All ER 89 (Denning J). Chesworth v Farrar  1 QB 407, where theclaimant was allowed to bring a restitutionary claim despite the fact that the tortious limitation period hadpassed, is better regarded as a case where the cause of action was the vindication of a proprietary right ratherthan wrongdoing.
-  Hambly v Trott (1776) 1 Cowp 371, 375; 98 ER 1136, 1139 (Lord Mansfield). 168 See Part V.