Abstract
Political parties are both private and public bodies. Some actions of political parties must be categorised as private to protect freedom of speech and association. This article argues, however, that it is sometimes necessary that political parties are understood as exercising public functions as well. When parties are exercising public functions, their actions then may be subject to judicial review. Currently, political parties have not been held to exercise public functions in the UK either for purposes of the Human Rights Act 1998 or common law judicial review. This article challenges the approach in UK law, particularly in Tortoise Media v Conservative Party [2023], which held that it was not even arguable that the selection of a Prime Minister by a political party was a public function. This article challenges this finding by offering a framework, drawn from current case law, for establishing when political parties are exercising public functions. The case law says that functions are public when bodies are 'operating as an integral part of a governmental framework'. These conditions were more than satisfied in Tortoise Media and offer a firm - albeit limited and context-contingent - basis for judicial review of actions by political parties.