(D) THE LAW OF UNJUST ENRICHMENT
The creation and nurturing of the unjust enrichment principle is the most significant legal development in English private law of the late twentieth and early twenty-first century. It is noteworthy that in its early years the judges, notably Lord Goff, spoke of the law of restitution rather than a law of unjust enrichment. Unjust enrichment used to be thought of as a concept, but we should now recognize that we have a distinct law of unjust enrichment. Unjust enrichment still operates as a legal principle rather than a cause of action, but the different rules relating to unjust enrichment are now sufficiently well developed that it is possible to identify a distinct body of law which is appropriately called unjust enrichment.
-  Ltd v Creditcorp Ltd, The Trident Beauty  1 WLR 161, 164; and Westdeutsche Landesbank Girozentrale vIslington LBC  AC 669, 697, where he spoke of an action of restitution. See also Lord Hutton inKleinwort Benson Ltd v Glasgow City Council  1 AC 153, 186.
-  See Woolwich Equitable Building Society v IRC  AC 70, 197 (Lord Browne-Wilkinson).
-  As Lord Hope described it in Sempra Metals Ltd v IRC  UKHL 34,  1 AC 561, .