The combined municipality and county of Oslo has had a parliamentary system of government since 1986. The supreme authority of the city is the City Council (''Bystyret''), which  has 59 seats. Representatives are popularly elected every four years. The City Council has five standing committees, each having its own areas of responsibility. The largest parties in the City Council after the 2015-elections are the Labour Party and the Conservatives, with 20 and 19 representatives respectively.