Over the last decade, the literature on left-wing movement parties has provided new insights into movement parties’ organizational structure, action repertoire, and framing. However, research on processes and mechanisms of activists’ shift from non-electoral strategy, based on social movements and NGOs, towards electoral strategy, based on political parties, remains scarce. Moreover, the existing research is typically based on successful cases, such as Podemos and Syriza, that developed in relatively favourable conditions. In order to further our understanding of the processes of movement party formation, this paper investigates the context of post-socialist Southeast Europe by providing an in-depth comparison of two recent cases of new left movement party formation: Initiative for Democratic Socialism (Slovenia) and Do Not Let Belgrade D(r)own (Serbia). Based on case studies, including the analysis of thirty interviews with activists, organizational documents, media reports, and protest event data, the paper outlines two distinct pathways of new left movement party formation in post-socialist Southeast Europe. In the Slovenian case, characterized by a high level of institutional openness and adequate discursive opportunities, the electoral new left was predominantly articulated as democratic socialist, with a focus on national-level electoral competition. In the Serbian case, characterized by an institutional framework closed for new challengers, as well as widespread discreditation of left-wing politics, the electoral new left predominantly took the pathway of green-left municipalism, with a primary focus on local-level electoral competition. The observed variation in these two pathways is used to discuss how differences across post-socialist contexts influence left-wing movements’ electoral strategy and the specific pathways of movement party formation.
