The Politics of Australia take place within the framework of a parliamentary democracy, with electoral procedures appropriate to a two-party system. Australia is governed as a federation and as a constitutional monarchy, with an adversarial legislature based upon the Westminster system. Australians elect parliamentarians to the Parliament of Australia, a bicameral body which is a hybrid of the parliamentary mechanisms carried over from the United Kingdom with the uniquely federalist element of the Australian Senate. Australia operates a system of compulsory voting.