The House of Commons is the lower house of the Parliament of the United Kingdom, which also comprises the Sovereign and the House of Lords (the upper house). Both Commons and Lords meet in the Palace of Westminster. The Commons is a democratically elected body, consisting of 650 members (since 2010 General Election), who are known as Members of Parliament (MPs). Members are elected through the first-past-the-post system by electoral districts known as constituencies. They hold their seats until Parliament is dissolved (a maximum of five years after the preceding election).
A House of Commons of England evolved at some point in England during the 14th century and, in practice, has been in continuous existence since, becoming the House of Commons of Great Britain after the political union with Scotland, and also, during the nineteenth century, of the United Kingdom of Great Britain and Ireland after the political union with Ireland, finally reaching its current title after independence was given to the Republic of Ireland. The House of Commons was originally far less powerful than the House of Lords, but today its legislative powers greatly exceed those of the Lords. Under the Parliament Act 1911, the Lords' power to reject most legislative bills was reduced to a delaying power. Moreover, the Government is primarily responsible to the House of Commons; the prime minister stays in office only as long as he or she retains its support. Almost all government ministers are drawn from the House of Commons and, with one brief exception, all prime ministers since 1902.
The full, formal style and title of the House of Commons is The Honourable the Commons of the United Kingdom of Great Britain and Northern Ireland in Parliament assembled.
Although it does not formally elect the prime minister, the position of the parties in the House of Commons is of overriding importance. By convention, the prime minister is answerable to, and must maintain the support of, the House of Commons. Thus, whenever the office of prime minister falls vacant, the Sovereign appoints the person who has the support of the House, or who is most likely to command the support of the House — normally the leader of the largest party in the Commons. (The leader of the second-largest party becomes the Leader of the Opposition.) In modern times, by convention, the prime minister is always a member of the House of Commons, rather than the House of Lords.
The Lower House may indicate its lack of support for the Government by rejecting a Motion of Confidence, or by passing a Motion of No Confidence. Confidence and no confidence motions are sometimes phrased explicitly, for instance: "That this House has no confidence in Her Majesty's Government." Many other motions were considered confidence issues, even though not explicitly phrased as such. In particular, important bills that form a part of the Government's agenda were formerly considered matters of confidence, as is the annual Budget. When a Government has lost the confidence of the House of Commons, the prime minister is obliged to either resign, making way for another MP who can command confidence, or request the monarch to dissolve Parliament, thereby precipitating a general election.
Except when compelled to do so by an adverse vote on a confidence issue, the prime minister is allowed to choose the timing of dissolutions with the permission of the Monarch, and consequently the timing of general elections. The timing reflects political considerations, and is generally most opportune for the prime minister's party. However, no parliamentary term can last for more than five years; a dissolution is automatic upon the expiry of this period unless an act of Parliament is passed extending the maximum term as happened during both World Wars. Parliament almost never sits for the maximum possible term, with dissolutions customarily being requested earlier.
A prime minister may resign even if he or she is not defeated at the polls (for example, for personal health reasons); in such a case, the premiership goes to whoever can command a majority in the House of Commons, in practice this is usually the new leader of the outgoing prime minister's party. Until 1965, the Conservative Party had no mechanism for electing a new leader and when Anthony Eden resigned as PM in 1957 without recommending a successor, the party was unable to nominate one. It fell to the Queen to appoint Harold Macmillan as the new prime minister, after taking the advice of ministers.
By convention, all ministers must be members of the House of Commons or House of Lords. A handful have been appointed who are outside Parliament but in most cases they subsequently entered Parliament either by means of a by-election or receiving a peerage. Since 1902, all prime ministers have been members of the Commons (the sole exception, the Earl of Home, disclaimed his peerage days after becoming prime minister, and was immediately elected to the House of Commons as Sir Alec Douglas-Home).
In modern times, a vast majority of ministers belong to the Commons rather than the Lords. Few major cabinet positions (except Lord Privy Seal, Lord Chancellor and Leader of the House of Lords) have been filled by a lord in recent times. Notable exceptions are Lord Carrington who served as Foreign Secretary from 1979 to 1982, and Lord Young who was appointed Employment Secretary in 1985. Lord Mandelson was appointed Secretary of State for Business, Enterprise and Regulatory Reform in October 2008; he was also briefly neither a member of the Lords nor Commons in this capacity. The elected status of members of the Commons, as opposed to the unelected nature of members of the Lords, is seen to lend more legitimacy to ministers. The prime minister chooses the Ministers, and may decide to remove them at any time; the formal appointment or dismissal, however, is made by the Sovereign.
The House of Commons scrutinises the Government through "Question Time", during which members have the opportunity to ask questions of the prime minister and of other cabinet ministers. Prime minister's question time occurs once each week, normally for a half-hour each Wednesday. Questions must relate to the responding minister's official government activities, not to his or her activities as a party leader or as a private Member of Parliament. Customarily, members of the Government party and members of the Opposition alternate when asking questions. In addition to questions asked orally during Question Time, Members of Parliament may also make inquiries in writing.
In practice, the House of Commons' scrutiny of the Government is fairly weak. Since the first-past-the-post electoral system is employed, the governing party often enjoys a large majority in the Commons, and there is often little need to compromise with other parties. Modern British political parties are so tightly organised that they leave relatively little room for free action by their MPs. Also, many ruling party MPs are paid members of the government. Thus, during the 20th century, the Government has lost confidence issues only three times — twice in 1924, and once in 1979. However, the threat of rebellions by their own party's backbench MPs often forces Governments to make concessions (recently over top-up fees and foundation hospitals). Occasionally the Government is defeated by backbench rebellions (Terrorism Act 2006). However, the scrutiny provided by the Select Committees is more serious.
The House of Commons technically retains the power to impeach Ministers of the Crown (or any other subject, even if not a public officer) for their crimes. Impeachments are tried by the House of Lords, where a simple majority is necessary to convict. The power of impeachment, however, has fallen into disuse: the House of Commons exercises its checks on the Government through other means, such as No Confidence Motions; the last impeachment was that of Viscount Melville in 1806.
Bills may be introduced in either house, though controversial bills normally originate in the House of Commons. The supremacy of the Commons in legislative matters is assured by the Parliament Acts, under which certain types of bills may be presented for the Royal Assent without the consent of the House of Lords. The Lords may not delay a money bill (a bill that, in the view of the Speaker of the House of Commons, solely concerns national taxation or public funds) for more than one month. Moreover, the Lords may not delay most other public bills for more than two parliamentary sessions, or one calendar year. These provisions, however, only apply to public bills that originate in the House of Commons. Moreover, a bill that seeks to extend a parliamentary term beyond five years requires the consent of the House of Lords.
By a custom that prevailed even before the Parliament Acts, only the House of Commons may originate bills concerning taxation or Supply. Furthermore, supply bills passed by the House of Commons are immune to amendments in the House of Lords. In addition, the House of Lords is barred from amending a bill so as to insert a taxation or supply-related provision, but the House of Commons often waives its privileges and allows the Lords to make amendments with financial implications. Under a separate convention, known as the Salisbury Convention, the House of Lords does not seek to oppose legislation promised in the Government's election manifesto. Hence, as the power of the House of Lords has been severely curtailed by statute and by practice, the House of Commons is clearly the more powerful branch of Parliament.
Today's Parliament of the United Kingdom largely descends, in practice, from the Parliament of England, although the 1706 Treaty of Union, and the Acts of Union that ratified the Treaty, created a new Parliament of Great Britain to replace the Parliament of England and the Parliament of Scotland. This new parliament was, in effect, the continuation of the Parliament of England with the addition of 45 MPs and sixteen Peers to represent Scotland. Later still the Act of Union (1800) brought about the abolition of the Parliament of Ireland and enlarged the Commons at Westminster with 100 Irish members, creating the Parliament of the United Kingdom of Great Britain and Ireland.