When studying the sources of law and the English legal system it is important to be aware of three main theories:
Parliamentary Sovereignty
The Separation of Powers
The Rule of Law
Parliamentary Sovereignty (AKA Supremacy)
According to AV Dicey in An Introduction to the Study of the Law of the Constitution 1885, Parliamentary Sovereignty consists of 4 elements:
1. Parliament may introduce any law it wishes
2. Parliament can not bind future Parliaments
3. Laws made by Parliament override all other forms of law
4. The courts must apply the laws made by Parliament.
Until 1972 the UK Parliament held Sovereignty. Parliament was only limited in its actions by political, media and public pressure. This contrasts with other jurisdictions where there exists a Bill of Rights granting the courts powers to advance the rights of the citizens above that of Parliament. However when we joined the EEC (now EU), Parliament handed over sovereignty to Europe to the extent that EU law now takes precedence over Acts of Parliament. Outside the areas of law that EU law operates Parliament retains supremacy. Most notably Parliament retained Sovereignty in relation to the European Convention on Human Rights when it introduced the Human Rights Act 1998.
The Separation of Powers
French Constitutional theorist, Montesquieu introduced the concept of the separation of powers in Spirit of the Laws 1748. According to Montesquieu, an ideal state should be divided in to three separate arms; the legislature (parliament), the executive (Government and Local Authorities) and the judiciary. Each of the arms should have their own separate function: Legislature - make law, executive - administer the law, Judiciary - apply the law. Each arm is to remain separate and not impinge on the others function. They should be balanced and able to check and limit the power of the other arms. Accordingly, if one arm of the state became all too powerful this would be indicative of an oppressive state and to the detriment of citizens.
In the UK constitution we do not strictly adhere to the separation of powers. The bulk of the law making is carried out by the executive through delegated legislation and our judges develop the law also. The theory of the separation of powers is influential in measuring how our constitution operates. Indeed the Constitutional Reform Act 2005, which among many other provisions replaces the House of Lords court with a new Supreme Court in Oct 2009, is aimed at strengthening the separation of powers.
See an interview with Lord Phillips Lord Chief Justice on judicial independence here.
The Rule of Law
The Rule of law is considered to be fundamental to all democratic legal systems and dates back to Aristotle, although popularised by AV Dicey. It encompasses basic freedoms including no punishment without infringement of the law, freedom from arbitrary power and arbitrary laws. The laws must be certain, legible and accessible to comply with the rule of law. It also militates against retrospective laws. The Rule of Law requires equality before the law ie all citizens are subject to the same law no matter what their rank or station in life.
