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All Heads of British Diplomatic Missions are bound by Diplomatic Service Regulations which are made under powers vested in the Secretary of State for Foreign and Commonwealth Affairs by the Diplomatic Service Order in Council 1991 (as amended). These include a Code of Ethics, the Diplomatic Service Code, which makes clear that the duty of all members of the Diplomatic Service is to the duly constituted Government of the United Kingdom. The Code also includes
“the duty to comply with the law, including international law and treaty obligations, and to uphold the administration of justice”.
This includes the applicable law of the UK and any international legal obligations of the UK. Without prejudice to their privileges and immunities, diplomats are also required by the Vienna Convention on Diplomatic Relations to respect the laws of the receiving State.