For much of the twentieth century, the United Kingdom was one of the most centralised of liberal democratic states. The Westminster Model of government was one in which power was concentrated at the centre. The doctrine of parliamentary sovereignty dictated that no other body could challenge parliament’s legislative supremacy. The fusion of the executive and legislative branches meant that a governing party commanding a majority in the House of Commons dominated the policy-making process. Aside from local government, which was relatively weak, there was no tier of government beyond the centre in Great Britain.