International law in general — Sources — Customary international law — Sovereign immunity — Principle of immunity of embassy funds from enforcement jurisdiction of receiving State — Decision of German Constitutional Court as evidence of customary international law — The law of England

International law in genera — Relation to municipal law — Sovereign immunity — Immunity from execution — Bank accounts in name of embassy — Construction of English legislation — State Immunity Act 1978 — Whether permissible to construe Act against background of principles of intemational law — Whether recourse to intemational law always permissible where municipal legislation applies to interState relations or only in the event of ambiguity in municipal legislation — Relevance of intemational customary and treaty law — Principle of customary law derived from accepted practice as evidenced by judicial decisions in other jurisdiction — Vienna Convention on Diplomatic Relations, 1961 — The law of England

States as international persons — In general — Sovereignty and independence — In foreign relations — Soverign immunity — Immunity from enforcement — Funds belonging to Republic of Colombia in London bank accounts — Certificate by Ambassador that funds in use for non-commercial purposes of meeting day to day running costs of Embassy — whether purpose commercial — State Immunity Act 1978 — Principles of international customary and treaty law on immunity from enforcement jurisdiction — The law of England

Diplomatic and consular intercourse and privileges — Permanent diplomatic envoys — Privileges and immunities of — Diplomatic envoys and their staff — Immunity from execution of embassy property — Bank account in name of embassy — Funds used for meeting running expenses of embassy — Whether funds in use for commercial purposes — Duty of receiving State to accord full facilities for functioning of diplomatic mission — State Immunity Act 1978 — The law of England

Jurisdiction — In general — Territorial — Exemptions from and restrictions upon — Foreign States — Sovereign immunity — Immunity from execution — Judgment creditor seeking to levy execution against foreign State by attachment of funds in foreign State's bank account in London — Whether permissible for English courts to exercise enforcement jurisdiction in this manner — State Immunity Act 1978 — Sections 3, 13 and 17 — Certificate of Ambassador stating that funds in question were in use for non-commercial purposes of meeting “expenditure necessarily incurred in the day to day running of the Diplomatic Mission” — Meaning of “commercial” — Relevance of principles of international law in construction of municipal legislation — Customary and treaty law on immunity of sending State from enforcement jurisdiction of receiving State — Vienna Convention on Diplomatic Relations, 1961 — Onus of proving property in use for commercial purposes — Evidential weight of certificate of head of diplomatic mission — The law of England