Constitutional Convention

A Convention is a long established, informal and uncodified procedural agreement followed by the institutions of state. Conventions are particularly important in countries like the UK which lack a written constitution, where they provide help in understanding how the state functions. They do not exist in any written document holding legal authority, but there will rarely be a departure from a convention without good reason.

Examples of a convention include the assumption that a government will resign if it loses a vote of confidence in the Commons, or the “Salisbury Convention” in the Lords, which is that the Lords will not oppose the second or third reading of any Government legislation promised in its election manifesto or those in the 2011 Cabinet Manual pertaining to what would happen in the case of a hung Parliament.

The recent row regarding tax credits has put to the test a convention that the House of Lords will not oppose a “money bill” proposed by the Government and passed in the House of Commons. When the Lords voted to delay this bill, they did so under the argument that tax credits were related to welfare, not just finance.

The difference between a convention and a law is that laws are enforced by courts, with legal sanctions following their breach, whilst conventions are enforced only by political pressure. Furthermore, laws are systematic, a set of rules bound together by other rules, whereas each constitutional convention stands alone. Conventions can become laws should Parliament choose to ‘crystallise’ them, such as in the 2011 Fixed Term Parliament Act, which formalised the convention that the Government should resign if they were defeated in a vote of confidence.