The United Kingdom constitution – a mapping exercise

It is often said that the constitution of the United Kingdom of Great Britain and Northern Ireland is “unwritten”, or even that it does not exist. In fact, much of the UK constitution is written down in some form, but it has never been codified or, as in most other countries, brought together in a single document. This makes the UK unusual but not unique: Israel and New Zealand also lack fully codified constitutions.

The academic J. A. G. Griffith once argued that the UK “constitution is what happens […] if it works, it’s constitutional”. It was, he concluded, essentially a “political constitution” rather than legal in nature. Christine Carpenter and Andrew Spencer have been more specific, defining a constitution as “the set of political, governmental and legal structures and shared values within which the business of everyday politics and governance operates”.

As the Supreme Court stated in its judgment on Miller II, the UK constitution has been:

established over the course of our history by common law, statutes, conventions and practice. Since it has not been codified, it has developed pragmatically, and remains sufficiently flexible to be capable of further development.

As this suggests, there are several “sources” of the UK constitution, which are introduced in the first section of this research briefing. These include legislation, the royal prerogative, case law and constitutional conventions. The last of these are captured in the pages of Hansard, government Command Papers and even The Times’ correspondence columns. In recent decades, conventions have been set out in official (but not legally binding) documents such as the Cabinet Manual and Ministerial Code. Some are frequently updated, for a flexible constitution is also an ever changing one.

This briefing then attempts to “map” the UK’s constitution, summarising the main statutes, prerogatives, conventions and case law in several recognised constitutional categories. The focus is on the constitution as it is rather than as it has been in the past; on describing aspects which are commonly referenced, most relevant and perhaps often misunderstood. There is also an attempt to capture various elements of what Walter Bagehot termed the “dignified constitution”, the UK’s often colourful ceremonial traditions.

Naturally, this is selective. As Sir Ivor Jennings observed in The Law and the Constitution, a writer on the UK constitution “selects what seems to him to be important”. And as Professors Andrew Blick and Robert Blackburn have observed, it is probably “not possible to establish with certainty and wide agreement what precisely are all the contents of the constitution”.

What this briefing is not is an attempt to codify the UK constitution. However, as Nick Barber has pointed out:

we should take care not to overestimate the differences between written and unwritten constitutions: large parts of the UK constitution are written, whilst large parts of the constitutions of states with a capital c Constitution lie outside of that document.

Above all, what follows is intended as a navigational aid to what can often appear an endless and impenetrable mass of constitutional information.