Cities of London and Westminster is a constituency returning a single Member of Parliament (MP) to the House of Commons in the United Kingdom Parliament. It is a borough constituency for the purposes of election expenses and type of returning officer. As with all constituencies, the election is decided using the first past the post system of election. Since its creation at the 1950 general election, the constituency has always elected the candidate nominated by the Conservative Party. It has been represented since 2001 by Mark Field.