I Congreso del Partido [1983] 1 AC 244

1973, after the assassination of Allende, Cubazucar, a Cuban enterprise, contracted to sell sugar to a Chilean Company. One shipment ‘Playa Larga’ owned by the Cuban government, left Valparaiso (acting on instructions from Cuban Government) without discharging the remainder of the cargo, which was later sold to someone else in Cuba. Marble Islands, Somali Flag, owned by Liechtenstein company, in its way to Valparaiso received instructions by Cuban government to sail to North Vietnam. During the journey it became a Cuban ship owned by Cuban government. I Congreso was arrested in British waters on the application of the plaintiffs, the Chilean owners of the cargos of Playa Larga and Marble Islands. Who had instituted proceedings in rem in the British courts for breach of contract. The Cuban government entered a defence of state immunity the claim of immunity was disallowed

Wilberforce: I have no doubt that the ‘restrictive’ doctrine [of immunity] should be applied to the present case, the issue is as to the limits of the doctrine. ‘Restrictive theory’ arises from the willingness of states to enter into commercial or other private law transactions with individuals. It appears to have two main foundations: a) it is necessary in the interest of justice to individuals having such transactions with states to allow them to bring such transaction before the courts b) to require a state to answer a claim based upon such transactions does not involve a challenge to or to inquire into any act of sovereignty or governmental act of the state. The appellants contended that we have here a commercial transaction. The fact that it is difficult to draw the line between sovereign and not sovereign state activities is no reason for abandoning the distinction. In considered under the ‘restrictive’ theory whether State immunity should be granted or not, the court must consider the whole context in which the claim against the state is made