The Constitution Explained

The United Kingdom constitution

The term constitution describes a set of principles and rules that form a basis for a political system.

It creates governmental institutions, defining and limiting their powers, and setting out the way in which they should interact with one-another. A constitution regulates the relationship between those organs and the public they are supposed to serve.

Most countries in the world include some of the key features of their constitutions in texts often referred to as ‘written’ or ‘codified’ constitutions. They are likely to have special legal status, with courts required to uphold the constitution even if to do so means annulling primary legislation. Typically, changes to the contents of ‘written’ or ‘codified’ constitutions can only take place if a demanding amendment procedure is met. The texts often have a special place in the culture of the countries they apply to.

The United Kingdom (UK) lacks such an entity. But nonetheless it has a constitution. The purpose of this page is to explain what it is.

Identifying the constitution

When we try to explain the constitution, if we do not have a specific text to consult, where should we look? It is found in a number of places:

Conventions: understandings about how the constitution should function. They can be hard to define precisely and in a way that commands wide agreement; and they lack hard legal force. But conventions are the source of some of the most important features of the UK system of government. For instance, that the Prime Minister should be a member of the House of Commons able to command the confidence of that institution is only a convention. Traditionally, conventions tended not to be written down in official documents. But, increasingly in recent decades, accounts of them have come to be included in texts published by bodies such as the UK government. These include the Cabinet Manual and the Ministerial Code.

Acts of the UK Parliament: another source for major aspects of the UK constitution is primary legislation passed by the UK Parliament. These laws provide for devolution, for the right to vote and the holding of elections, for the prohibition of discrimination, for the existence of the UK Supreme Court; and much else. Yet from a practical viewpoint there is little to distinguish constitutional statutes from more regular laws dealing with, for instance, education or transport. An Act of Parliament can also vest significant discretionary authority – including, through statutory instruments, the ability to create new, secondary, legislation – in institutions or individuals such as ministers in the UK government. Such power is exercised subject to limited parliamentary scrutiny; and is constitutionally significant since it can imply a strengthening of the UK government (or executive) at the cost of Parliament.

The law and custom of the UK Parliament: the rules according to which the UK Parliament operates, enforceable by the parliamentary authorities. They regulate the ways in which Parliament carries out, on behalf of the public, core constitutional functions such as passing laws and holding the UK government to account.

Judicial decisions

Technically, it is the job of courts to interpret the rules, not to make them. But in practice, through identifying what the law is, judges can create it. In the process they have established important features of the UK constitution. Courts have helped develop important concepts such as individual rights and the idea that public authorities are subject to limitations and do not possess arbitrary power. In recent years, through the two Miller cases, the UK Supreme Court has affirmed (respectively in 2017 and 2019) the position of the UK Parliament in the political system of the UK.

International law

The UK tends towards what is known as a ‘dualist’ arrangement in its relationship with international law. This tendency means that, to have direct internal force, international law must be provided for specifically by domestic legal measures such as Acts of Parliament. Treaties, for instance, are supposed to bind the UK as a state on the international stage, and only form part of UK law if it is incorporated into it. This approach contrasts with what is known as the ‘monist’ model, under which international agreements automatically enter into the legal hierarchy of the countries that are party to them. Though it is indirect, treaties can have an important constitutional impact. The Human Rights Act 1998, for instance, is a major piece of constitutional legislation, the purpose of which is to incorporate the European Convention on Human Rights into UK law. International law also helps form the background of assumptions that inform courts in their deliberations. They tend to proceed on the basis that, unless they make their intention to do so clear, legislators did not intend to contravene international law.

The views of constitutional authorities

As we have seen, the UK constitution is defined in a scattered way. Making it out precisely can be difficult. Consequently, the views of expert observers who seek to impose some kind of coherence upon it can be of particular value. They can become so influential to perceptions of the system that they seem to become part of it. The views of the late nineteenth/early twentieth century legal scholar, Albert Venn Dicey, for instance, came to underpin the widely accepted doctrine known as ‘parliamentary sovereignty’. The political journalist, Walter Bagehot, writing in the nineteenth century, helped shape the conception and operation of a constitutional monarchy. Such constitutional authorities continue to be important today.