The Cabinet Manual is a government document in the United Kingdom which sets out the main laws, rules and conventions affecting the conduct and operation of the Government of the United Kingdom. It was written by Her Majesty's Civil Service, led by Cabinet Secretary Sir Gus O'Donnell, and was published by the Cabinet Office on 14 December 2010. The Manual gives an overview of the UK's system of government, reflecting the importance of Parliament, Cabinet government and the democratic nature of the UK’s constitutional arrangements by explaining the powers of the Executive, Sovereign, Parliament, international institutions (most notably the European Union), the Crown Dependencies, British Overseas Territories and the devolved administrations in Northern Ireland, Scotland and Wales. The Manua