The House of Commons

The House of Commons is the elected heart of the United Kingdom’s political system. It is the chamber from which governments are made and unmade, where laws are debated and passed, and where ministers must answer in public for what they do. Its 650 Members of Parliament are sent there by voters in every corner of the country, and it is precisely because they are elected that the Commons is the dominant of Parliament’s two Houses.

Composition: MPs and constituencies

The Commons consists of 650 Members of Parliament, each elected to represent a single constituency — a defined geographical area. MPs are chosen using First Past the Post: in each constituency the candidate with the most votes wins the one available seat, whether or not they secure an overall majority of votes cast. General elections must take place at least every five years.

An MP represents everyone in the constituency, not only those who voted for them. The job combines two roles. Nationally, MPs scrutinise the government, debate and vote on legislation, and may serve as ministers or on committees. Locally, they handle constituents’ problems — known as casework — and act as a channel between the area and Westminster. Constituency boundaries are reviewed periodically so that electorates remain roughly equal in size.

The Speaker

Presiding over the chamber is the Speaker, elected by MPs from among their own number. The Speaker chairs debates, decides who may speak, enforces the rules of the House and maintains order, with the power to discipline members who breach the rules. The defining feature of the office is impartiality: on election the Speaker sets aside party allegiance entirely and must be seen to treat all sides fairly. The Speaker does not take part in debate and does not normally vote, casting a vote only to break a tie, and even then by established convention rather than personal preference.

Debates and divisions

The Commons reaches decisions through debate followed, where necessary, by a vote. In debate, MPs address the chair rather than one another and speak in turn when called by the Speaker, following long-standing conventions of courtesy. Debate allows ministers to set out and defend policy and allows other members to question, challenge and propose alternatives before anything is decided.

When a question is contested, the House holds a division — its method of recording a formal vote. Members walk through one of two lobbies, “Aye” or “No”, and are counted by tellers, after which the result is announced. Most divisions follow party lines, organised by the whips — MPs appointed by each party to manage attendance and encourage members to support the party’s position. A “three-line whip” marks a vote of the highest importance. Even so, MPs are ultimately free to vote as they judge right, and rebellions do occur.

Sustaining and scrutinising government

The Commons performs two great constitutional functions in relation to the executive. The first is to sustain the government. By convention the monarch appoints as Prime Minister the person best able to command the confidence of the Commons — normally the leader of the largest party. The government can only continue to govern, and pass its programme, while it retains majority support. If it loses a vote of no confidence, convention holds that it must resign or seek a general election. This is the ultimate accountability of the executive to the elected chamber.

The second function is to scrutinise. The Commons subjects the government to continuous challenge through several mechanisms:

• Questions to ministers, including the weekly Prime Minister’s Questions, urgent questions and ministerial statements, which force ministers to explain decisions on the floor of the House.
• Debates on government policy and on motions tabled by the opposition or backbenchers.
• Select committees — cross-party groups of backbench MPs that examine the work, spending and policy of individual departments. They take evidence, question ministers and officials, and publish reports with recommendations. The government is not obliged to accept their conclusions, but the public exposure they bring is a powerful discipline.

The Commons and legislation

Almost all legislation must pass the Commons, moving through readings, line-by-line committee scrutiny and votes. As the elected chamber it has the decisive say. Under the Parliament Acts 1911 and 1949 it can ultimately pass most legislation without the agreement of the House of Lords, and it holds sole authority over money bills dealing with taxation and spending. This financial supremacy reflects a foundational constitutional principle: that taxation and public spending require the consent of the people’s elected representatives.

Taken together, these features make the Commons the central institution of British democracy — the place where the will of the electorate is translated into a government, where that government is held to account, and where the laws of the land are made.