In this presentation, made at a DBIS seminar on trade union membership, we analyse the continued decline of trade unions and examine the possible implications for workers, employers, and unions themselves. The research focuses particularly on the fortunes of trade unions in the decade or so since New Labour first came to power. It assesses the extent and nature of changes in union membership and bargaining coverage since the late 1990s, and also examines trends in union effects on wages, non-wage benefits and workplace performance.