New Zealand is a representative democracy. Members of the unicameral New Zealand Parliament gain their seats through nationwide general elections, or in by-elections. General elections are usually held every three years; they may be held at an earlier date (a "snap" election) at the discretion of the prime minister (advising the governor-general), although it usually only happens in the event of a vote of no confidence or other exceptional circumstances. A by-election is held to fill a vacancy arising during a parliamentary term. The most recent general election took place on 17 October 2020.