n Britain, a Member of Parliament is known as an MP. Specifically, MPs are members of the House of Commons, the lower house in the British bicameral legislature system. They are democratically elected by residents of the districts which they represent, and once elected they serve a term of four to five years in Westminster, acting as legislators and representing the interests of the British people

In order to serve as an MP, someone must be over 18 and a British citizen or a citizen of a Commonwealth nation. In addition, he or she must not be bankrupt or subject to certain legal actions. Certain people are excluded from running for the House of Commons because of their positions; current serving military, and certain Crown officials, for example, may not run for election. In addition, an MP must be mentally sound.

Someone who wants to run as an MP generally runs with the sponsorship of a specific political party, and is required to file paperwork indicating his or her intent to run. Political campaigns by MPs typically include advertising, public events, debates, and other schemes to get them in the public eye. Many MPs have some sort of experience in working with the law or in government, although this is not required.

The length of an MP's term in Parliament is generally around five years. By tradition, Parliament is dissolved by the monarch in cooperation with the Prime Minister for the purpose of holding an election to bring new Members of Parliament in. By British law, a parliament cannot sit for more than five years, so these dissolutions usually take place at five year intervals. When the House of Commons meets at the start of a new term, a speaker is elected to supervise their meetings, and he or she typically serves for the entire five year term.

The British legislature is extremely complex, and it has a number of interesting quirks. For example, an MP may not officially resign from the House of Commons, since he or she has agreed to serve a constituency. However, when an MP does need to leave office, he or she can engage in a legal fiction by applying for a position to serve the Crown which will exempt the MP from service in the House of Commons. Two Crown positions are typically used for this purpose: the Crown Steward and Bailiff of the Manor of Northstead, and Steward and Bailiff of the Chiltern Hundreds. These positions are sinecures, meaning that the person in office need not do any work, but because they would create a conflict of interest with serving in Parliament, they effectively allow an MP to resign.