This chapter examines the relevance of social movement unionism for organised labour relations in Germany. It starts out from the thesis that industrial relations are increasingly regulated in two worlds. While in the first world protected wage labour, co-determination and collective agreements are still the norm, this is no longer the case in the second world of deregulated, precarious work. This forces trade unions to adopt and apply elements of a social movement unionism. This takes place within the framework of a new conflict formation, where struggles often take place workplace by workplace and company by company. The article introduces the conceptual debate around social movement unionism and establishes it on the basis of the so-called Jena Power Resource Approach. By means of empirical studies of selected labour disputes, the article then sketches an outline of the new conflict formation. The article concludes that the old social capitalism cannot be restored, despite some trade union successes. It argues for a reorientation of labour relations research and for a systematic investigation of innovative approaches to trade union renewal, including practices of social movement unionism.