Party System (organisation of politics)

This definition of party system refers to the political party system – an essential part of the working of the British constitution, which depends on the existence of organised political parties, presenting policies to the electorate. Although parties are not registered in law, most candidates in elections belong to one of the main parties, which in the UK includes the Conservative, Labour, Liberal Democrats, UKIP, SNP, Plaid Cymru, Democratic Unionist Party and the Green Party.

The way the political party system works is that the party that wins most seats at a general election, or which has the support of a majority of MPs usually forms the Government, with 100 of its members in the House of Commons and House of Lords receiving ministerial appointments. The largest minority party becomes the official Opposition with its own leader and a ‘shadow’ cabinet.

In Parliament the Government and Opposition sit on either side of the Commons chamber (which is why we are said to have an ‘adversarial’ party system. The leaders sit on the front benches with their supporters sitting on the backbenches behind them. This is similar in the House of Lords, although some Lords don’t have a political party association so sits on the ‘cross benches’.

The general aim of the party system in Parliament is for the Opposition to constructively criticise policy formulation (with questions from thefloor of both houses and in committees), oppose the government on proposals it considers objectionable (seeking to amend them or vote them down) and to formulate their own policies to try to win at the next General election.