This book examines the way that trade unions make policy and in particular the roles of members and leaders. It uses the policy of the Transport and General Workers' Union towards the decasualization of deck labour in the UK as a case study, tracing the different views expressed, the actions taken by dissatisfied members and the response of union leaders. It is argued that the experience of this case study points to the danger of attempting to develop a single, all-embracing theory of policy making in trade unions which does not take into account the myriad of different contexts, strategies and responses to them.