The constitution of a country is a set of rules regulating the powers of its government and the rights and duties of its citizens. Many nations have been forced to draw up a written constitution in response to a revolution, war or as a step towards independence. In contrast, the United Kingdom which has had a relatively stable history has an unwritten constitution developed over many centuries with sources of varying importance which include statute and common law, conventions and traditions, written works of importance and international law. The UK constitution is often described as ‘partly written and wholly uncodified’. A codified constitution is one in which key provisions are collected together in a single legal document.
Whether written or unwritten, a constitution must have one supreme power over and above all other power in the state. Under a written constitution, the highest source of power is the supreme Constitution as interpreted by the Supreme Court. As the UK has no single written document as supreme authority, in theory, the highest source of authority in the UK is the Parliament, and the Acts of Parliament are the highest form of law. Parliamentary sovereignty and the rule of law were described by the legal scholar Albert Venn Dicey as the two pillars of the UK constitution.
A V Dicey defined the Parliamentary doctrine in his book Introduction to the Study of the Law of the Constitution (1885), as the doctrine where parliament can make or unmake any law on any subject whatever, without legal restriction, although Dicey was prepared to recognise that the electorate might have ‘political sovereignty’ by the election of Members of Parliament, so that the opinion of the people can be legally expressed through Parliament, and Parliament alone, and no person or body is recognised by the law as having a right to override or set aside the legislation of parliament.
The liberal democracies established in Europe based their constitutions on the principle that ultimate authority was vested in the people so that they must then be involved in constitutional change. In constitutional terms, Britain never developed the idea of popular sovereignty. In the traditional legal doctrine of parliamentary sovereignty, democracy is not a requirement and the UK Parliament determines the system of government. The sovereignty of Parliament is simply recognised by the courts as a rule of the common law, established by ordinary precedents. The political notion of the ultimate sovereignty of the electorate in Parliamentary sovereignty must be distinguished from the legal doctrine of the legislative supremacy, where the courts owe their allegiance to the latter and the courts will take no notice of the will of the electors. Judicial notions of justice must generally give way to those expressed by parliament where they are inconsistent. However the legal authority of statute depends on its compatibility with the central core of the shared political morality, such as Acts passed by an unrepresentative Parliament, or Acts which undermined democracy or even acts which are inconsistent with fundamental ideas if justice and fairness, as no neat distinction between legal doctrine and political principle can be sustained at that level of adjudication. Dicey recognised political reality in what he called constitutional conventions that are united in character by the possession of a single purpose – to secure that Parliament is ultimately subject to the wishes of the electorate, where he observed that ‘ if Parliament be in the eye of the law supreme legislature, the essence of representative government is, that the legislature should represent or give effect to the will of the political sovereign, i.e of the electoral body, or of the nation’. Dicey presents conventions as a means of harmonizing legal and political sovereignty, which remain conceptually distinct. The legal doctrine of sovereignty is the most fundamental of our constitutional conventions. Section 4 of the Human Rights Act 1998 has reduced Parliamentary sovereignty to an extent, so that the courts are now able to declare that legislation is incompatible with certain rights in the European Convention of Human Rights which have been incorporated into UK law by that Act. The European Union has a written constitution in the various Treaties which govern its operation and, the UK courts must have regard to these when applying EC law. EU law can override Acts of Parliament, but it is important to remember that all EC law only has any effect in the UK due to its incorporation via s.2 of the European Communities Act 1972. In the case of McCarthy’s v Smith (1979) Lord Denning made the point that if the EC Act was repealed, then EC law would lose its force as far as the British judiciary were concerned.
The doctrine of the rule of law may be interpreted as a philosophy or political theory which lays down fundamental requirements for law, or as a procedural device by which those with power rule under the law, rather than a precise concept defined by the courts. However, whereas parliamentary sovereignty is a fully legal concept enforced by the courts, the rule of law merely pervaded the constitution as an unwritten principle. The rule of law underlies the entire constitution and acts as a yardstick for measuring the extent in which the government acts under the law and the extent to which individual rights are recognised and protected by law. The purpose of law is to enable citizens to live within the law, and the law must be clear if it is capable of being obeyed. In this respect, it is only meaningful to speak of the rule of law in a society which features a democratically elected, responsible and responsive government and it is often used as a justification for separating legislative from judicial power. The case of Entick V. Carrington  19 St Tr 1030, Court of Common Pleas, validated Dicey’s theory on the rule of law that the citizens are free to do anything that is not specifically prohibited under law, but governmental agents are prohibited from doing anything that is not specifically allowed by case law or statute. However, due to Parliamentary Sovereignty, the rule of law does not limit Parliament which can simply enact a new law and so then rule of law would then come second place to Parliamentary sovereignty.
The separation of powers is one of the pervasive principles of the UK constitution. Separation of powers is a principle set out by Charles Montesquieu where he stated that without a separation of powers there could be no liberty where liberty means ‘the right of doing whatever the law permit’. It denotes the premise that there are three main organs of government, the legislative whose function is for the making of general rules, the executive whose function is to govern according to the rules and the judiciary for resolving disputes between parties according to the law and that there should be a system of checks and balances between each branch. The most significant perceptions can be accomplished from the political philosopher John Locke who took the view that protection of the liberties of the subject required that the government: ‘ought to be exercised by established and promulgated laws; that both the People may know their duty, and be safe and secure within the limits of the law, and the Rulers too kept within their due bounds, and not to be tempted by the power they have in their hands to employ it to purposes.’ (Two Treaties on Government, Book 2 Chapter XI). The separation of powers protects liberty to avoid any concentration of power so that power cannot corrupt and it enables the citizen to be sure that the law made by the legislature will bind the executive and be applied by the judiciary. The idea of there being three different areas where the law is created is in theory so that no one function has too much power, which could lead to the power being abused and create the risk of tyranny. This concept has its fullest practical expression in the US constitution that has proven to be a stable political system, and yet there have been other Presidential systems that have been open to tyrants and dictators. If we examine the UK constitution it can be seen to have many violations of the doctrine with a weak separation of powers where the chief executive who is the Prime Minister, forms a subset of the legislature (Parliament), as did the judiciary until the establishment of the Supreme Court of the United Kingdom, and yet the Parliamentary system has proven a fairly stable form of liberal democracy. Although a fusion exists, the doctrine does not imply that the branches of government be completely independent. There are certain checks and balances which are in place, and these are mainly concerned with the limit to the exercise of executive powers. They include the independence of the judiciary, the accountability of the government to parliament, the House of Lords and the system of statute rules that have constitutional significance e.g. The European Community’s Act 1972 and the Human Rights Act 1998 which has made the rights of citizens more simple and clear.
Often a written constitution will have a rigid structure that will ‘entrench’ parts to protect important values or the structure of the constitution, and can only be amended in accordance with a special procedure. In the UK all that is required for a change in any part of the law would be an Act of Parliament passed in the ordinary manner (although a change in EC law requires complex voting requirement). If a party has a majority in the House of Commons they can change the constitution. The continued legitimacy of government depends not only on what a constitution says, but also on its continued responsiveness to shared beliefs and continued popular consent, and so the UK Constitution is described as flexible. Since the introduction of devolution measures in 1997, the UK has a unitary Constitution in that the UK Constitution permits the national legislature to amend a subordinate constitution of the Scottish Parliament.
If the United Kingdom has a constitution then its characteristics include: Uncodifed not entrenched, flexible and unitary. In my view, the UK does have a constitution which may not be as clear cut as many other nations but it is still acknowledged.
Introduction to the Study of the Law of the Constitution (1885), AV Dicey.
Cases & Materials on Constitutional and Administrative Law, Allen and Thompson, 9th edition, Oxford. Pages 45, 47.
Constuitutional & Administrative law, 7th edition, Hilaire Barnett, Routledge-Cavendish. Page 73.
Two Treaties on Government, Book 2 Chapter XI.
The European Community’s Act 1972
Section 4 of the Human Rights Act 1998
Entick V. Carrington  19 St Tr 1030, Court of Common Pleas.