There has been significant growth of precarious work in Britain over the past three decades. This article examines the strategies adopted by unions to counteract this trend. It uses Weil’s ‘strategic choice framework’ to assess the attempts of the Trades Union Congress to encourage affiliates to adopt innovative ways of reaching precarious workers and examines the extent to which these strategies have been implemented. Unfavourable external shifts have placed greater pressure on unions to develop appropriate internal strategies and structures to strengthen their capacity for reaching precarious workers. The Trades Union Congress has encouraged unions to use community unionism strategies to organise precarious workers outside of the workplace and sustainable sourcing strategies to regulate their conditions through procurement mechanisms. These strategies are relatively effective means of reaching precarious workers in the context of legal constraints on unions and changes in the organisation of work and production. The internal governance structures of the British union movement need to be reformed if these strategies are to be adopted more widely.