Abstract This introduction to the special issue reviews research on party politics, social movement organisations, and political activism and identifies gaps in research on radical left mobilisation in the twenty-first century. First, this introduction provides a definition of radical left cooperation, and outlines key theoretical concepts which can help to advance its study. It explains why such cooperation is likely to be conditioned by contextual social, political, and economic factors. Second, it outlines the structure and contributions of the special issue. It concludes by discussing the key findings and how their insights advance the study of radical left cooperation.
Charalambous et al. (Sun,) studied this question.