This article analyses the state of play regarding party funding reform in British Politics through the application of new institutionalism. It then investigates whether the Collins Review of 2014 represents a critical juncture in the evolution of the political finance regime. Utilising elite interview and documentary research, the article argues that the removal of a key institutional stumbling block – the concession of the opt-in for trade union members of the Labour party – has created a situation which may have a very real effect on both British party funding and how we understand party finance reform more generally.