(ii) United Kingdom
The United Kingdom of Great Britain and Northern Ireland (UK) has a unitary government. This differs from a 2-tiered federal system, such as Australia and the USA, where the Constitution divides authority between a central (federal) government and state governments.
The UK has no such Constitution.136 The Parliament at Westminster holds the unrestricted power of law-making (Sovereignty of Parliament), and the UK Parliament has no limits on the subject matter on which it may legislate.137 Thus, the UK national government can delegate responsibilities to subordinate bodies, such as regional and local authorities, at will. This means that local authorities in the UK can act only within the power conferred to them by the national government. In contrast, the federal Constitutions of Australia and the USA confer original authority directly to the state governments. Only an amendment to the Constitution can change this.
The absolute authority of the UK Parliament and the supremacy of English law have, however, retracted somewhat since the UK joined the European Communities in 1973.138 By enacting the European Communities Act 1972, and its later amendments, the UK has transferred certain rights and obligations arising under the EU/EC treaties from its domestic legal system to the legal system of the European Union. As a result, the UK government has accepted that, within the limits of the powers conferred to the EU, UK law is no longer the supreme source of law; overriding European legislation restricts it.139 This means that EU law prevails over conflicting national provisions.140
Although the content of EU law covers fewer subjects than UK law, EU law's impact has expanded considerably. Initially concerned essentially with economic activity, the EU legal competence now also comprises many other subjects, such as the environment and health. Only the provisions of the EC/EU treaties, drafted in very general terms, limit its scope.
136 The UK has no single constitutional document. Acts of Parliament, common law, and conventions comprise the sources of the UK Constitution.
137 See Neil Parpworth and David Pollard, Constitutional and Administrative Law (4th ed, 2006) 75.
138 The European Communities originally consisted of the European Coal and Steel Community (ECSC), which expired in 2002, the European Atomic Energy Community (Euratom), and the European Economic Community (EEC). In 1993, the Maastricht Treaty (Treaty on European Union) established the European Union (EU) and renamed the EEC the 'European Community' (EC). The UK ratified the Maastricht Treaty in 1993. Today, the EU consists of the 2 remaining European Communities (first pillar), comprising the EC and Euratom, the common foreign and security policy (second pillar), and the police and judicial cooperation in criminal matters (third pillar). The Treaty on European Union (EU Treaty) and the Treaty Establishing the European Community (EC Treaty) constitute the competence of the EU and the EC. For more information on the EU, see European Commission, 'How the European Union Works—Your Guide to the EU Institutions' (2005) (http://europa.eu.int/comm/publications) (accessed 30 June 2007); Pascal Fontaine, 'Europe in 12 Lessons' (2006) (http://ec.europa.eu/publications) (accessed 30 June 2007); Neill Nugent, The Government and Politics of the European Union (6th ed, 2006); Richard Ward and Amanda Wragg, Walker and Walker's English Legal System (9th ed, 2005) 110–46.
139 UK courts have the power to overturn executive actions, delegated legislation, and Acts of Parliament if the legislation does infringe European law; see, for example, Factortame v Secretary of State for Transport(No 2)  1 AC 603.
140 European law consists of primary and secondary legislation. The Treaty on European Union (EUT) and the Treaty on Establishing the European Community (ECT) form part of the primary legislation, which defines the scope of the competence of EU/EC institutions (The Council of the European Union and the European Council, the European Parliament, and the European Commission). The EC Treaty confers legislative power to the EC institutions to make secondary legislation in accordance with the provisions of the Treaty. It thereby distinguishes different types of legislation: directives, regulations, decisions, recommendations, and opinions; see Art 249 ECT. EU regulations directly apply in all member states, and bind in their entirety. This means that they automatically form part of UK law without any further national enactment. Directives, however, do not directly apply and need further implementation by an Act of Parliament or secondary legislation to take effect. Decisions bind in their entirety on all those the decisions address. Recommendations and opinions do not bind and, therefore, do not form part of EU law. However, their legal status lacks full clarity since the Court of Justice of the EC has only occasionally referred to them. The case law of the Court of Justice of the European Communities provides another source of EU law.