3.3.2 British practice Customary international law : As far as the rules of customary international law are concerned the English courts have generally adopted the doctrine of incorporation. Provided that they are not inconsistent with Acts of Parliament or prior authoritative judicial decisions, then rules of customary international law automatically form part of

doi:10.4324/9781843143802-11

Chapter

3.3.2 British practice Customary international law

ABSTRACT

It is quite true that whatever has received the common consent of civilised nations must have received the assent of our country, and that to which we have assented along with other nations in general may properly be called international law, and as such will be acknowledged and applied by our municipal tribunals when legitimate occasion arises for those tribunals to decide questions to which doctrines of international law may be relevant. But any doctrine so invoked must be one really accepted as binding between nations, and the international law sought to be applied must, like anything else, be proved by satisfactory evidence, which must shew either that the particular proposition put forward has been recognised and acted upon by our own country, or that it is of such a nature, and has been so widely and generally accepted, that it can hardly be supposed that any civilised state would repudiate it. The mere opinions of jurists, however eminent or learned, that it ought to be so recognised, are not in themselves sufficient. They must have received the express sanction of international agreement, or gradually have grown to be part of international law by their frequent practical recognition in dealings between various nations ... Barbuit’s Case, Torquet v Bath and Heathfield v Chilton are cases in which the Courts of law have recognised and given effect to the privilege of ambassadors as established by international law. But the expressions used by Lord Mansfield when dealing with the particular and recognised rule of international law on this subject, that the law of nations forms part of the law of England, ought not to be construed so as to include as part of the law of England opinions of text-writers upon a question as to which there is no evidence that Great Britain has ever assented, a fortiori if they are contrary to the principles of her laws as declared by her Courts. The cases of Wolff v Oxholm (1817) and R v Keyn are only illustrations of the same rule – namely, that questions of international law may arise, and may have to be considered in connection with the administration of municipal law.