Parliamentary sovereignty refers to the absolute and unlimited legal authority of Parliament, reflected in its ability to make, amend or repeal any law it wishes. As the parliamentary authority Blackstone put it, ‘what Parliament doth, no power on earth can undo’. Parliamentary sovereignty is usually seen as the central principle of the UK constitution. Parliamentary sovereignty is based on four conditions:
• The absence of a codified constitution – the absence of higher law
• The supremacy of statute law over other forms of law – Acts of Parliament outrank common law, case law, and so on
• The absence of rival legislatures – no other bodies have independent law-making powers
• No Parliament can bind its successors – Parliament cannot make laws that cannot be unmade.
Sovereignty defines the location of supreme constitutional power. If constitutions define the duties, power and functions of the various institutions of government, the sovereign body, or any body that shares sovereignty, has the ability to shape or reshape the constitution itself. In this way, it defines the powers of subordinate bodies. In the UK, sovereignty is located in Parliament or, technically, the ‘Crown in Parliament’. Parliamentary sovereignty is strictly a form of legal sovereignty: it means that Parliament has the ability to make, unmake or remove any law it wishes. As J. S. Mill (1806–73) put it, ‘Parliament can do anything except turn a man into a woman’.
However, there are doubts about the accuracy and continuing relevance of parliamentary sovereignty. This is for three reasons:
• Parliament is not, and has never been, politically sovereign. Parliament has the legal right to make, amend or unmake any law it wishes, but not always the political ability to do so. A simple example would be that Parliament could, in theory, abolish elections, but this would be likely to result in widespread public protests, if not popular rebellion.
The main political constraints on parliamentary sovereignty therefore include the following:
• Powerful pressure groups, especially major business interests
• Public opinion, particularly electoral pressures
• The views of major trading partners, notably the USA and leading EU states
• The policies of international organisations, such as the EU, the World Trade Organization (WTO) and the UN.
• There has been a shift from parliamentary sovereignty to popular sovereignty. Evidence of the growth of popular sovereignty can be seen, for example, in the wider use of referendums , the establishment of popularly elected devolved assemblies and in more clearly defined citizen’s rights, particularly through the Human Rights Act
• Parliament may no longer be legally sovereign. This view has developed primarily as a result of the constitutional implications of EU membership. It is also implied by the idea that devolution has resulted in ‘quasi-federalism’, reflected in the reluctance (or inabilty) of Parliament to challenge decisions made by devolved bodies.