Sovereign immunity — Restrictive theory — Whether part of modern International law — Whether applicable in English courts — Distinction between acta iure imperii and iure gestionis — Whether based upon nature or purpose of transaction — Agencies of foreign State — Central Bank — Whether entitled to sovereign immunity

International law in general — Relation to municipal law — Customary international law — Whether part of the law of England — Whether English courts entitled to give effect to changes in the rules of international law — Doctrines of transformation and incorporation — Doctrine of binding precedent — Applicability when English courts consider international law — The law of England