The Centralist Republic of Rainier is a multi-party democracy. In the lower house of the Congressional Houses parties are directly elected in general elections using a additional members voting system. The two most dominant parties are the one-nation conservative National Union Party and the Social Democratic Labour Party. Important minor parties include the liberal Radical Party, right-wing populist Reform Party and eco-socialist Green-Left Movement. There are several smaller parities in Rainier that have made little impact outside of local elections.