In January 2019, the High Court in Unions NSW v New South Wales [2019] HCA 1 ruled that legislation which substantially reduced the electoral expenditure limit for third-party campaigners was unconstitutional and invalid. The case directly impacts on campaign spending for the State election in March 2019. This e-brief outlines the events preceding the introduction of the Electoral Funding Act 2018 and examines the relevant provisions, the concept of the implied freedom of political communication in the Constitution, the reasoning of the High Court, and the implications of the case.