government with a prime minister and two houses of parliament
The parliament is bicameral, consisting of an upper house (the House of Lords) and a lower house (the House of Commons). The Sovereign forms the third component of the legislature (the Queen-in-Parliament). The House of Lords includes two different types of members: the Lords Spiritual, consisting of the most senior bishops of the Church of England, and the Lords Temporal, consisting mainly of life peers, appointed by the Sovereign on the advice of the Prime Minister, and of 92 hereditary peers, sitting either by virtue of holding a royal office, or by being elected by their fellow hereditary peers. Prior to the opening of the Supreme Court in October 2009, the House of Lords also performed a judicial role through the Law Lords.