Introduction
A constitution can be defined as the set of rules, principles, and practices that establish the main institutions of the state, define their powers, and regulate the relationship between them and the individual. Constitutions can be categorised as either codified or uncodified. A codified constitution, like that of the United States, is one where the fundamental rules are contained within a single, authoritative document. In contrast, the United Kingdom has an uncodified constitution, meaning its rules are found across a variety of sources. This is largely a result of the UK’s history of gradual political evolution, which avoided the revolutionary moments that often trigger the creation of a single constitutional document (King, 2007).
The sources of the UK constitution are both legal and non-legal. Legal sources include Acts of Parliament, such as Magna Carta 1297 or the Human Rights Act 1998, and common law established through judicial precedent. Non-legal sources are equally important and include authoritative works by constitutional scholars and constitutional conventions. This essay will argue that constitutional conventions are a vital component of the UK's constitution. It will explain their nature as non-legal rules, discuss why they are generally obeyed, their role in controlling prerogative powers and providing flexibility, and conclude by considering proposals for their reform.
The Nature of Constitutional Conventions
Constitutional conventions are best understood as unwritten, non-legal rules of constitutional behaviour that are considered to be binding on those who operate the constitution. They regulate the conduct of the sovereign, ministers, Parliament, and the civil service. As they are not laws, they are not enforced by the courts. The judiciary may recognise the existence of a convention, but it will not enforce it. In Madzimbamuto v Lardner-Burke [1969] 1 AC 645, the Privy Council acknowledged a convention that the UK Parliament would not legislate for Southern Rhodesia on matters within its competence without its consent, but held that this did not limit Parliament's legal power to do so. The breach of a convention does not lead to legal sanctions; instead, the consequences are political.
To identify a convention, the classic test was proposed by Sir Ivor Jennings. He suggested a three-part test: first, what are the precedents; second, did the actors in the precedents believe they were bound by a rule; and third, is there a reason for the rule? (Jennings, 1959). This test emphasises that conventions are more than just habits; they are practices underpinned by a belief in their obligatory nature and a functional purpose. Marshall and Moodie offered a slightly different perspective, defining conventions as "rules of constitutional behaviour which are considered to be binding by and upon those who operate the constitution" (Marshall and Moodie, 1971, p.23). This highlights the subjective acceptance of the rules by political actors.
The Role of Conventions in the UK Constitution
Conventions perform several critical functions, most notably by ensuring that the government operates in a democratic and responsible manner. A key role is the regulation of the Royal Prerogative powers. These are historical, discretionary powers held by the Crown which are now, by convention, mostly exercised by government ministers.
For example:
- Royal Assent: The monarch holds the legal prerogative power to refuse to assent to a bill passed by Parliament. However, a long-standing and absolute convention dictates that the monarch must always grant Royal Assent. The last time assent was refused was in 1708 by Queen Anne. This convention ensures that the will of the democratic legislature prevails over the hereditary monarch.
- Appointment of the Prime Minister: The Queen has the legal power to appoint whomever she chooses as Prime Minister. In practice, convention dictates that she must appoint the individual who is best able to command the confidence of the House of Commons, which is almost always the leader of the political party with a majority of seats.
- Appointment of Ministers: The monarch formally appoints government ministers, but convention requires that this is done solely on the advice of the Prime Minister.
- Deployment of Armed Forces: The power to deploy troops abroad is a prerogative power. Following the controversy over the 2003 Iraq War, an emerging convention suggests that the House of Commons should have the opportunity to debate and vote on the decision before committing forces to military action, except in an emergency (Cabinet Manual, 2011).
Conventions also provide the constitution with essential flexibility. Because they are not legally binding statutes, they can evolve over time or be suspended in exceptional circumstances without a formal amendment process. A clear example is the convention of collective ministerial responsibility, which holds that all ministers must publicly support government policy or resign. This convention promotes government unity. However, it has been suspended on several occasions, notably during the 2016 referendum on EU membership, to allow ministers to campaign on opposing sides without resigning (Gee and Peele, 2016). This flexibility allows the constitution to adapt to political pressures in a way that a rigid, codified rule could not.
Why Are Conventions Obeyed?
Given that conventions carry no legal force, a central question is why they are so consistently followed. Jennings (1959) provided the classic explanation, arguing that they are obeyed because a breach would lead to such significant political trouble that it would likely culminate in a breach of the law. His example was that if a government lost a general election but refused to resign (a breach of convention), Parliament would eventually refuse to pass the annual Finance Act. Without this law, the government could not legally collect taxes, and its administration would grind to a halt.
Beyond this, the primary reason for adherence is political. A government or minister who breaches a significant convention would face severe political consequences. They would be accused of acting 'unconstitutionally' and could expect condemnation from the opposition, the media, and the public. This could damage their reputation, undermine their authority, and ultimately lead to a loss of political office. Therefore, conventions are obeyed because political actors have a vested self-interest in maintaining the stable and predictable system of rules from which they derive their authority.
Reform and Codification
In recent years, there has been a trend towards writing down or 'codifying' conventions. A prime example is the Cabinet Manual, first published in 2011, which is a government document that records many of the key conventions affecting the executive, ministers, and the monarch. While it is not a law and does not make the conventions legally enforceable, it provides clarity and an authoritative reference point.
In some instances, conventions have been converted into law. The Ponsonby Rule, a 20th-century convention that treaties should be laid before Parliament for 21 days before ratification, was put onto a statutory footing by the Constitutional Reform and Governance Act 2010. This change provides Parliament with a stronger, legally guaranteed role in scrutinising treaties.
There is an ongoing debate about whether more conventions should be formally codified. Proponents argue that codification would bring greater certainty, transparency, and accountability to the constitution, potentially allowing judges to enforce these important rules. However, opponents caution that codification would sacrifice the flexibility that is a key strength of conventions. It could lead to a less adaptable system and might draw the judiciary into resolving what are essentially political disputes, potentially damaging judicial neutrality (Barber, 2018).
Conclusion
In conclusion, constitutional conventions are a fundamental, albeit paradoxical, feature of the United Kingdom's constitutional arrangements. They are not laws and are not enforced by the courts, yet they provide the essential operating instructions that ensure the legal framework of the state functions democratically. Their importance is most evident in how they control the exercise of archaic prerogative powers, ensuring power lies with elected representatives rather than the hereditary monarch. They are obeyed not because of legal sanction, but because of the powerful political consequences of a breach. While their unwritten nature provides valuable flexibility, allowing the constitution to adapt without formal amendment, it also creates uncertainty. The modern trend towards recording conventions in documents like the Cabinet Manual, or even turning them into law, reflects a desire for greater clarity. However, the debate over further codification continues, balancing the desire for certainty against the proven benefits of a flexible and politically responsive constitutional order.
References
Barber, N. (2018) The Principles of Constitutionalism. Oxford: Oxford University Press.
Cabinet Office (2011) The Cabinet Manual. 1st edn. [Online] Available at: https://www.gov.uk/government/publications/cabinet-manual.
Gee, G. and Peele, G. (2016) 'The Dogs That Didn't Bark: The Collective Inaction of Britain's Political and Legal Constitution in the Face of the Brexit Referendum', German Law Journal, 17(S1), pp. 51-70.
Jennings, I. (1959) The Law and the Constitution. 5th edn. London: University of London Press.
King, A. (2007) The British Constitution. Oxford: Oxford University Press.
Marshall, G. and Moodie, G.C. (1971) Some Problems of the Constitution. 5th edn. London: Hutchinson.
Cases
Attorney General v Jonathan Cape Ltd [1976] QB 752.
Madzimbamuto v Lardner-Burke [1969] 1 AC 645.
Legislation
Constitutional Reform and Governance Act 2010.
Human Rights Act 1998.
Magna Carta 1297.
