The doctrine of parliamentary supremacy was summarised by Dicey in three points:
Parliament can make law concerning anything. - this is in contrast to the position in many countries where the acts of the legislature can be struck down for conflicting with the Constitution (as can happen in the USA after the Supreme Court claimed the power in Marbury v Madison)
No Parliament can bind a future parliament (that is, it cannot pass a law that cannot be changed or reversed by a future Parliament) - put another way, no incoming Parliament is bound by previous parliaments. Again this contrasts with other countries where certain rules are 'entrenched' - meaning the rule can either never be repealed (as with the French Constitution Art 89 "The republican form of government shall not be the object of any amendment") or requires special procedures to amend ( such as Art 5 of the US Constitution requiring 2/3rd of all States or 2/3rd of both House of Congress to propose an amendment - and ratification of the amendment by3/4th of all state legislatures)
A valid Act of Parliament cannot be questioned by the court. Parliament is the supreme lawmaker.
There is a very useful article on recent developments on Wikipedia (NOT A SOURCE I WOULD GENERALLY USE OR TRUST) - but whoever the author was, they have produced a useful resource.
Recent developments
Parliamentary sovereignty prevents judicial review of primary legislation passed by Parliament. However, in the late 20th and early 21st centuries, the notion of parliamentary supremacy was modified under the influence of five principal sources: The devolution of power to regional assemblies in Scotland (Scottish Parliament), Wales (Welsh Assembly) and Northern Ireland (Northern Ireland Assembly). All three assemblies can pass primary legislation within the areas that have been devolved to them. As the system remains devolved and not federal, the powers of these assemblies stems from the UK Parliament and can be suspended.
The UK's membership of the European Economic Community, later the European Union, from 1973. The EU represents, as the European Court of Justice ruled in 1963 in the case Van Gend en Loos, a "new legal order of international law for the benefit of which the [Member] States have limited their sovereign rights, albeit within limited fields". The UK became part of that legal order - though the fact that UK membership of the EU has been brought about through Acts of Parliament - principally the European Communities Act 1972 - raises the possibility that Parliament could, as a matter of UK law, pass further legislation unilaterally withdrawing the UK from the Union, or selectively barring the application of European law within the UK. {As subsequent events have shown!}
Following the case of Thoburn v Sunderland City Council certain statutes are protected as Constitutional Statutes. The case involved amendments to the Weights and Measures Act 1985 by the Weights and Measures Act 1985 (Metrication) (Amendment) Order 1994 pursuant to Directive 80/181/EEC. This stated that Imperial measurements could be displayed so long as the metric measurements were displayed in larger type beside them. Thoburn was convicted for only using Imperial measurements. In his defence he argued that allowing even limited use of Imperial measurements was in contravention of the relevant directive and therefore in contravention of Section 2(2) of the European Communities Act 1972. This would have invoked the doctrine of implied repeal which is essential to the doctrine of Parliamentary Sovereignty. In his judgment, Lord Justice Laws held that certain statutes of constitutional importance including Magna Carta and the European Communities Act 1972 could not be repealed by implied repeal. As such, this has slightly limited Parliament's sovereignty.
The enactment of the Human Rights Act 1998 which incorporates part of the European Convention on Human Rights into domestic law. The Act gives UK courts the power to issue a declaration of incompatibility where they believe that the terms of an Act of Parliament are in contravention of the rights guaranteed by the Act. The effect of the declaration is not to annul the Act but send a signal to Parliament which may then choose to amend the offending provision. As with the UK's membership of the European Union, the principle of parliamentary supremacy means that Parliament can at any time vote to repeal the Act and indeed the UK's ratification of the Convention itself.
The increasing use of referendums. Although the result of a referendum is in no way binding on Parliament unless it has previously agreed that this will be case, in practice there will be considerable pressure on Parliament from the electorate to take the result into account.
However, Parliament may withdraw from the most of the commitments it has made or repeal any of the constraints it has imposed on its ability to legislate. Thus, Parliament theoretically remains almost entirely sovereign. The qualifier "almost" is provided because in 1921, after a century of dispute, Parliament passed the Church of Scotland Act 1921 which finally agreed that it does not have sovereignty over the Church of Scotland, the established church in Scotland.
There is a concept in political science of 'legal' and 'political' sovereignty. It can be argued that legal sovereignty has not been lost, because Parliament still retains all its theoretical powers. There are no legal limits on Parliament's sovereignty. However, as it is highly unlikely that the UK would repeal the European Communities Act and leave the EU, and it is unlikely the devolved legislature would be abolished, there are significant political limits on the sovereignty of Parliament. Nevertheless, it remains the case that the UK Parliament could do so without seeking the mutual consent of the EU or the devolved legislatures, as it did with the abolition of the Parliament of Northern Ireland in 1972, and that if it did, these repeals would be legally and politically binding.
This stands in contrast to the Acts of Parliament which have been used to grant independence from the UK to former dominions and colonies in the British Empire. Following the Balfour Declaration, the Statute of Westminster 1931 established a status of legislative equality between the self-governing dominions of the British Empire and the United Kingdom, and provided that Acts passed by the UK Parliament would not apply in the dominions without a dominion's express consent. It is difficult to see how the UK could later resile from that position. By way of further example, the UK Parliament passed the Canada Act 1982 which stated that the UK Parliament would no longer be able to amend the Canadian constitution. If the UK parliament were to repeal or amend the Canada Act 1982, it would be unenforceable as Canada is no longer subject to UK sovereignty.
Of course this year we have had the decision in R (Miller) v Sec of State for Exiting the European Union. A Must Read!!!
