The Lords Commissioners are privy counsellors appointed by the monarch of the United Kingdom to exercise, on his or her behalf, certain functions relating to Parliament which would otherwise require the monarch's attendance at the Palace of Westminster. These include the opening and prorogation of Parliament, the confirmation of a newly elected Speaker of the House of Commons and the granting of royal assent. The Lords Commissioners are collectively known as the Royal Commission. The Royal Commission includes at least three—and usually five— Lords Commissioners. In current practice, the Lords Commissioners usually include the Lord Chancellor, the Archbishop of Canterbury, the leaders of the three major parties in the House of Lords, the convenor of the House of Lords Crossbenchers and the Lord Speaker. Occasionally there are substitutions if the normal commissioners are unavailable.

The Parliament of the United Kingdom of Great Britain and Northern Ireland is the supreme legislative body of the United Kingdom, and may also legislate for the Crown Dependencies and the British Overseas Territories. It meets at the Palace of Westminster in London. 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 three parts acting together to legislate may be described as the King-in-Parliament. The Crown normally acts on the advice of the prime minister, and the powers of the House of Lords are limited to only delaying legislation; thus power is de facto vested in the House of Commons.