This article is part of the series: Politics and government of the United Kingdom
The Constitution of the United Kingdom is the uncodified body of law which constitutes the rules for how the country functions. It consists mostly of written sources, including statutes, judge made case law and international treaties. Because of the lack of a single codified constitutional document, the UK constitution is commonly mislabelled as an "unwritten constitution". For the most part it is written, but is not redacted or reduced into a single document.. The constitution is based on the concept of all sovereignty ultimately belonging to Parliament (Parliamentary sovereignty), so the concept of entrenching particular rights, privileges or rules cannot exist. Statutory law is often considered the most important source of the constitution. The UK constitution leaves more constitutional conventions unwritten than other liberal democratic constitutions, with the exceptions of New Zealand and Israel.

Sovereign: Queen Elizabeth II
Parliament

• State Opening of Parliament
  House of Lords
  
  
  
  • Lord Speaker: Baroness Hayman
    House of Commons
    
    
    
    • Speaker: Michael Martin
      Prime Minister's Questions
      Her Majesty's Government
      The Privy Council
      Cabinet
      
      
      
      • Prime Minister: Gordon Brown
        Chancellor: Alistair Darling
        Foreign Secretary: David Miliband
        Home Secretary: Jacqui Smith
        Lord Chancellor: Jack Straw
        Full list of members
        Government departments
        The Civil Service
        Her Majesty's Loyal Opposition
        
        
        
        • Leader: David Cameron
          Shadow Cabinet
          Courts of the United Kingdom
          
          
          
          • Courts of England and Wales
            Courts of Northern Ireland
            Courts of Scotland
            Constituent countries
            Politics of Scotland
            
            
            
            • Scottish Parliament
              Scottish Executive
              Politics of Wales
              
              
              
              • National Assembly for Wales
                Welsh Assembly Government
                Politics of Northern Ireland
                
                
                
                • Northern Ireland Assembly
                  Northern Ireland Executive
                  Politics of England
                  
                  
                  
                  • English Regional Assemblies
                    Reserved matters
                    Local government
                    Greater London Authority
                    Elections: 2001 - 2005 - 54th
                    
                    
                    
                    • Parliament constituencies
                      Political parties
                      Constitution
                      Human rights
                      Foreign relations
                      EU Politics Government and Parliament
                      Since there is neither entrenched constitutional law nor a formal separation of powers, Parliament has the ability to change almost any aspect of the constitution at will. The constitution is therefore often spoken of by political scientists as being "organic;" that is, it has "evolved" over time since its medieval origins. but have ruled on constitutional matters whereby two statutes are in conflict - most notably with regards European matters. The courts also have jurisdiction over the extent of Royal Prerogative where not limited by statute.
                      For instance, until recently, there was no modern statute or document that attempted to codify the rights of citizens (e.g. freedom of speech) in the UK, common law precedents being the main source of "rights", referred to as 'civil rights'. Now, through the adoption of European Union law, and the European Convention on Human Rights, citizens are deemed to have certain negative rights that were previously unspecified in the legal system. These are enacted in the European Communities Act 1972 and Human Rights Act 1998, respectively. Constitutional reform has been particularly rapid in the past decade, and include the Human Rights Act; devolution of powers of government to Scotland, Wales and Northern Ireland; a significant reform of the House of Lords and a Freedom of Information Act.
                      
                      Flexibility
                      The UK constitution draws from a variety of written document and unwritten constitutional convention. The sources are of varying importance, with the written Acts of Parliament (statutes) and EU law being of greatest importance, regulating many aspects of government, and wider systems such as the running of elections. Foreign treaties, which are passed as Acts of Parliament, are also often of constitutional importance. As the United Kingdom uses the common law legal system, precedents established by judges also form a source of the constitution. Other important unwritten sources are Constitutional conventions, which, for example, attempt to establish lines of accountability for ministers. Many such conventions are ancient in origin, and form some of the principles of the constitution. Much about these conventions has been written, and guidelines for ministers and parliamentarians are today available in some detail in writing, despite his party not having a majority in Parliament. Queen Elizabeth II exercised her prerogative after extensive consultation with the Privy Council. Royal prerogatives are often controversial, since they give the government great theoretical power. However, the Royal Prerogative is not unlimited; this was established in the Case of Proclamations (1611), which confirmed that no new prerogative can be created and that Parliament can abolish individual prerogatives.
                      
                      Sources
                      
                      Acts of Parliament
                      
                      
                      
                      • Treaties
                        EU law
                        Common Law
                        Conventions
                        Royal Prerogative
                        Works of authority Summary list
                        The key principles of the constitution are its underlying features. The two most important principles of the British constitution were first established to exist as the "twin pillars" of the constitution by A.V. Dicey, in his work An Introduction to the Study of the Law of the Constitution (1885). They are that the constitution is built on the twin equal principles of Parliamentary sovereignty and Rule of law. The former means that Parliament is the supreme law making body, it alone can make legislation on a national level. This is an ancient principle, and can be traced clearly from the Restoration, and before. The latter is the principle of equal application of the law: 'everyone is equal before the law'. Although the theory is certainly ancient, from the Magna Carta, 1215 in practice equal application of the law to every subject/citizen in the state only seriously developed from the nineteenth century. Dicey's "twin pillars" interpretation is a legalistic interpretation, and has been criticised by commentators writing about the decline of Parliament's independence and the dominance of the executive in policy making. Though political interpretations of the UK constitution have changed much since Dicey's era, there is no consensus on an alternative legal interpretation.
                        Another important principle is the concept of a unitary state, which is a corollary of Parliamentary sovereignty, and means that unlike in federal or confederal systems, sovereignty resides only at the centre of the state. The power of local and devolved bodies are totally dependent on Acts of Parliament, they could be abolished completely by Parliament if it wished. Constitutional monarchy is a key principle, meaning that the monarch does not technically rule but has a ceremonial role only. This principle traces from Restoration, and by the time Walter Bagehot wrote that the monarchy was the 'dignified parts' of the constitution, the modern situation had been established. However, this is tempered by the fact that parliament technically derives its authority from the Crown by the implicit consent of the monarch. The collective term for the legislative and governmental power of parliament is therefore the King (or Queen) in Parliament principle. This means that the monarch is often described as the "supreme guardian of the constitution" in that he or she could overturn an unconstitutional act of parliament by decree. This is extremely unlikely to happen, however; although the Crown, in theory, can govern by decree, such an act would enable parliament to force an abdication under the power it established and proved during the Abdication Crisis of 1936, when Parliament forced King Edward VIII to abdicate. The monarch, therefore, has an established role to advise, warn, and encourage ministers, although the Crown's executive powers remain unused.
                        The most recent major principle of the constitution is European Union membership, the principle that EU law takes precedence over UK law. This principle was famously identified in the Factortame case in which the Merchant Shipping Act 1988 was overturned. This appears to undermine the principle of Parliamentary sovereignty, but Parliament could still withdraw from the EU by repealing the European Communities Act 1972 so in a way Parliamentary sovereignty is preserved.
                        
                        Key principles
                        
                        A.V. Dicey's "Twin pillars" of the constitution
                        
                        
                        
                        • Parliamentary sovereignty (ancient origins, modern evolution started from the Restoration)
                          Rule of law (ancient origins, modern evolution started in the nineteenth century)
                          Other important principles
                          
                          
                          
                          • Unitary state (ancient origins, derived from monarchy)
                            Constitutional monarchy (originated from the Restoration)
                            EU membership (from 1972, primacy of EU law established in 1990) Summary list
                            While some might assert that the UK does not have a constitution, the vast majority of theorists describe the 1688 compromise between crown and parliament as a constitution, which is the basis of the textbook view described in this article. In one article, Lord Scarman presents a spirited argument for a written constitution for the UK, but still refers to the 1688 compromise and resulting acts of parliament as a constitution.[1]
                            The UK Constitution has no fundamental written source, and is ever changing. It relies much on unwritten convention. Dicey himself identified that ultimately "the electorate are politically sovereign," and Parliament is legally sovereign. A Constitution would impose limits on what Parliament could do without a legal majority. To date, the Parliament of the UK has no limit on its power other than the possibility of extra-parliamentary action (by the people) and of other sovereign states (pursuant to treaties made by Parliament and otherwise).
                            
                            Disputes about the nature of the UK Constitution
                            Because the United Kingdom adheres to the principle of parliamentary sovereignty, there is no hierarchy in statutory Acts of Parliament. But clearly for most people the Representation of the People Act 1918 is more important than the Zoo Licensing Act 1981 (unless, perhaps, you are a zookeeper). In Thoburn v Sunderland City Council Lord Justice Laws from the High Court decided that he would try to establish a principle of law on this matter, that the United Kingdom courts ought to recognise a hierarchy.
                            "In the present state of its maturity the common law has come to recognise that there exist rights which should properly be classified as constitutional or fundamental... And from this a further insight follows. We should recognise a hierarchy of Acts of Parliament: as it were "ordinary" statutes and "constitutional" statutes. The two categories must be distinguished on a principled basis. In my opinion a constitutional statute is one which (a) conditions the legal relationship between citizen and State in some general, overarching manner, or (b) enlarges or diminishes the scope of what we would now regard as fundamental constitutional rights. (a) and (b) are of necessity closely related: it is difficult to think of an instance of (a) that is not also an instance of (b). The special status of constitutional statutes follows the special status of constitutional rights. Examples are the Magna Carta, the Bill of Rights 1689, the Act of Union, the Reform Acts which distributed and enlarged the franchise, the HRA, the Scotland Act 1998 and the Government of Wales Act 1998. The ECA clearly belongs in this family. It incorporated the whole corpus of substantive Community rights and obligations, and gave overriding domestic effect to the judicial and administrative machinery of Community law. It may be there has never been a statute having such profound effects on so many dimensions of our daily lives. The ECA is, by force of the common law, a constitutional statute."
                            This was wholly obiter dicta (i.e. not relevant to the case at hand and so not binding precedent), and entirely unfounded. Regardless of whether a rule of law ought to exist, it does represent a significant body of opinion that believes certain legal foundations ought not to be open to reevaluation. Below is a list of some more key statutes, commonly held as of high importance.
                            
                            Key statutes and conventions
                            
                            Magna Carta (1215)
                            Habeas Corpus Act 1679
                            Bill of Rights 1689 - for England and Wales
                            Claim of Right 1689 - for Scotland
                            Act of Settlement 1701
                            Act of Union 1707 - union of the Kingdom of England & the Kingdom of Scotland to form the Kingdom of Great Britain
                            Act of Union 1800 - union of Great Britain & Ireland to form the United Kingdom of Great Britain and Ireland
                            Reform Act 1832
                            Reform Act 1867
                            Reform Act 1884
                            Parliament Acts (of 1911 and 1949)
                            Representation of the People Act 1918
                            Government of Ireland Act 1920
                            Irish Free State (Agreement) Act 1922, Irish Free State Constitution Act 1922, and Irish Free State (Consequential Provisions) Act 1922
                            Royal and Parliamentary Titles Act 1927
                            Representation of the People Act 1928
                            Statute of Westminster 1931
                            Representation of the People Act 1949
                            Life Peerages Act 1958
                            Representation of the People Act 1969
                            European Communities Act 1972
                            Northern Ireland Constitution Act 1973
                            Human Rights Act 1998
                            Scotland Act 1998
                            Government of Wales Act 1998
                            Northern Ireland Act 1998
                            House of Lords Act 1999
                            Freedom of Information Act 2000
                            Constitutional Reform Act 2005
                            Government of Wales Act 2006 Selected key statutes
                            
                            Relating to monarchy
                            
                            
                            
                            • The Sovereign shall grant the Royal Assent to all Bills passed by Parliament (the Royal Assent was last refused by Queen Anne in 1708, for the Scottish Militia Bill 1708).[2]
                              The monarch will not dissolve Parliament without the advice of the Prime Minister.
                              The monarch will ask the leader of the dominant party in the House of Commons to form a government, and if there is no dominant party, the leader most likely to be able to form a government.
                              The monarch will ask a member of the House of Commons (rather than the House of Lords or someone outside Parliament) to form a government. It remains possible, however, for a caretaker Prime Minister to be drawn from the House of Lords.
                              All ministers are to be drawn from the House of Commons or the House of Lords.
                              The House of Lords will accept any legislation that was in the Government's manifesto (the 'Salisbury Convention') – in recent years this convention has been broken by the Lords.
                              Individual Ministerial Responsibility
                              Collective Ministerial Responsibility Some important conventions
                              The Labour government under Prime Minister Tony Blair instituted sweeping constitutional reforms in the late 1990s and early-to-mid 2000s. The incorporation of the European Convention on Human Rights into UK law has granted citizens specific negative rights and given the judiciary some power to enforce them. The courts can encourage Parliament to amend primary legislation that conflicts with the Act by a "declaration of incompatibility," and courts can refuse to enforce or "strike down" any incompatible secondary legislation. Any actions of government authorities that violate Convention rights are illegal except if forced to by an Act of Parliament.
                              Recent reforms have also decentralised the UK by setting up a devolved parliament in Scotland and assemblies in Wales and Northern Ireland. Devolution has challenged the tradition of the UK being a centralised, unitary state, which indeed it never was since Scotland and Ireland (until 1801) always had separate governments or legal systems. Some commentators have stated the UK is now a "quasi-federal" state.
                              These reforms have undermined the concept of Parliamentary sovereignty somewhat, even though Parliament could still abolish the devolved assemblies and repeal the Human Rights Act. In reality such action is unlikely so these restrictions on the legislative power of Parliament are likely to remain on the statute book for the time being.
                              The passing of an unprecedented Freedom of Information Act has challenged the traditional British notion that governments should not disclose too many details of its operations.
                              The government has shown a desire to abolish the position of Lord Chancellor, a position that unusually combines executive, legislative and judicial power in conflict with the notion of the separation of powers. This however has been defeated in the House of Lords. A further apparent breach of separation of powers, the presence of Law Lords (members of the judiciary) in the House of Lords, will be removed by moving the Lords to the new Supreme Court of the United Kingdom by 2009. Ironically separation of power was a concept described by the French philosopher Montesquieu after analysing the contemporary British constitution, which reflected the way in which the constitution actually operated. He did not necessarily anticipate a separation of offices, but was rather describing the separation of functions.