Politics of the United Kingdom
The UK Parliament is the supreme legislative body in the United Kingdom (i.e., there is parliamentary sovereignty), and Government is drawn from and answerable to it. Parliament is bicameral, consisting of the House of Commons and the House of Lords. There is also a devolved Scottish Parliament and devolved Assemblies in Wales and Northern Ireland, with varying degrees of legislative authority.
List of political parties in the United Kingdom
Since then the Conservative and Labour parties have dominated British politics, and have alternated in government ever since. However, the UK is not quite a two-party system as other parties have significant support. The Liberal Democrats were the third largest party until the 2015 general election when they were overtaken by the Scottish National Party in terms of seats and UK political party membership, and by the UK Independence Party in terms of votes.