Parliament possesses legislative supremacy and thereby holds ultimate power over all other political bodies in the United Kingdom and the Overseas Territories. While Parliament is bicameral , it has three parts: the sovereign , the House of Lords , and the House of Commons. The House of Commons is the elected lower chamber of Parliament, with elections to single-member constituencies held at least every five years under the first-past-the-post system.
Most Cabinet ministers are from the Commons, while junior ministers can be from either house. The House of Lords is the upper chamber of Parliament, [ 10 ] comprising two types of members. The most numerous are the Lords Temporal , consisting mainly of life peers appointed by the sovereign on the advice of the prime minister, [ 11 ] plus up to 92 hereditary peers.
The less numerous Lords Spiritual consist of up to 26 bishops of the Church of England. Before the establishment of the Supreme Court of the United Kingdom in , the House of Lords performed judicial functions through the law lords. The Parliament of the United Kingdom is one of the oldest legislatures in the world, and is characterised by the stability of its governing institutions and its capacity to absorb change.
The Parliament of Great Britain was formed in following the ratification of the Treaty of Union by Acts of Union passed by the Parliament of England established and the Parliament of Scotland c. The principle of ministerial responsibility to the lower house Commons did not develop until the 19th centuryβthe House of Lords was superior to the House of Commons both in theory and in practice.
Members of the House of Commons MPs were elected in an antiquated electoral system , under which constituencies of vastly different sizes existed. Thus, the borough of Old Sarum , with seven voters, could elect two members, as could the borough of Dunwich , which had almost completely disappeared into the sea due to land erosion. Many small constituencies, known as pocket or rotten boroughs , were controlled by members of the House of Lords peers , who could ensure the election of their relatives or supporters.
