Politics & Government
Constitutional Conventions and the Royal Prerogative
Quick fact
The royal prerogative powers of the British monarch—such as summoning Parliament or appointing judges—are formally held by the Crown, but a set of unwritten constitutional conventions dictates that the monarch must follow the advice of the prime minister, effectively transferring real power to elected officials.
Why this is interesting
Every time a British prime minister decides to declare war, dissolve Parliament, or sign an international treaty, they are exercising powers that technically belong to the Queen. How is it that the monarch never actually vetoes these decisions, yet the system still works?
Read the full explanation
Understanding Constitutional Conventions and the Royal Prerogative
To understand how the royal prerogative is regulated, think of it as a set of legal buttons and switches that control the machinery of state. The 'owner' of the machine—the Crown—holds the actual buttons, but there is a strict operating manual—constitutional conventions—that says the owner must always press those buttons according to the instructions of the prime minister or other ministers. These instructions are not written down in law; they are sourced from political practice and long-standing tradition. For instance, the monarch has the legal power to withhold assent to a bill, but the convention is that the monarch always gives assent. Similarly, the monarch prorogues Parliament on the advice of the prime minister. These conventions make the prerogative powers politically accountable, because they are exercised by those who answer to Parliament, and ultimately to the electorate.
A deeper explanation
Constitutional conventions are the essential lubricant that prevents the engine of state from grinding to a halt. They are rules of political practice that are regarded as binding by the actors who operate the constitution, though they are not enforced by courts. The royal prerogative is a residual source of legal power that historically belonged to the monarch, but has over time come to be exercised by the government of the day. The core mechanism at work is that conventions impose a non-legal duty on the monarch to act on the advice of the prime minister, and on the government to seek parliamentary approval in certain contexts, such as before engaging in armed conflict. This ensures that the use of prerogative powers aligns with the principle of parliamentary sovereignty and democratic accountability. The lack of legal enforceability is deliberate: it allows flexibility in the constitution, but it also means that conventions are only as strong as the political commitment to uphold them. When a convention is broken, the remedy is political—such as resignations or electoral punishment—rather than judicial. This demonstrates the deep tension between legal form and political reality in an unwritten constitution.