The regional decentralisation of government has been persistently advocated in Britain, but none of the attempts to move in this direction has had any success. The comprehensive proposals published on behalf of the Social Democratic Party in July 1982 are taken as a basis for examining why this reform theme nevertheless persists. The assumptions underlying the call for regional government in Britain are set out and then examined in the context of West German federalism. It is argued that the main assumptions in the British case for regional decentralisation were of relatively little importance in the reshaping of a federal system in West Germany, nor have they had much influence on the subsequent consolidation of such a system. Further light is thrown on the obstacles to decentralisation in Britain by considering some of the centralising tendencies which have actually been reinforced after the structural reform of local government. The conclusion is that proposals for extensive regional decentralisation in Britain fail because they work against the grain of British experience in the structuring of government.