What is a by-election?

A by-election is specifically a special election that occurs to fill a vacancy that has arisen in Parliament between general elections. Such vacancies may arise due to various reasons, such as the resignation or death of a sitting Member of Parliament (MP). By-elections are significant because they allow voters in a particular constituency to select a new representative, ensuring that the representation in Parliament remains up to date and responsive to the electorate's needs.

This process is different from a general election, which is a larger event held at regular intervals to elect all MPs across the country. Additionally, by-elections do not occur annually, and they are not limited to local council elections, which pertain to different levels of government. Therefore, the definition of a by-election as a special election to fill a vacancy accurately reflects its role within the UK's electoral system.