Foreign sovereign — Act of foreign State — Principle of English law — Relationship to U.S. doctrine — Nature and extent of principle in English law — No application to extra-territorial acts of foreign sovereign — Legislation of foreign State — Laws of penal and discriminatory character — Recognition by English courts

Contract — Sale of sugar — Seller a company created by Cuban Government with responsibility for all external trade transactions relating to sugar and for ensuring compliance with International Sugar Agreement — Seller not a department of Cuban State and enjoying independent legal personality — Buyer a private company majority of shares in which held by Chilean State trading organisation — Effect of coup d’état in Chile — Withdrawal of vessel discharging — Diversion of vessel on high seas — Suspension of shipments — Frustration — Effect of Cuban legislation freezing Chilean assets — Effect of directive ordering suspension of contract shipments to Chile — Ability of Cuban company to rely on plea of frustration where frustrating event is act of Cuban Government — Coup d’état as frustrating event — The law of England