Literature on collective action increasingly investigates the role of thematic communication (i.e., what is being said) such as narratives and frames to explain collective action. Yet, only little is know about the role that structures of discourse (i.e., deliberative capacities including inclusivity, authenticity, and consequentiality) play for the constitution of collective action. To theorize this relationship, we conducted a single longitudinal case-study, analyzing the media-based public discourse about COVID-19 in the U.K.. We contribute to theory on collective action by unpacking the role of discursive structures for the constitution of collective action. We theorize from our data that collective action is importantly driven by “deliberative capacities” in media-based public discourse evolving in entanglement with “changing trust in collective action executing institutions”, “changing trust in science”, and “emerging imaginaries about the future”. Additionally, we advance theory on deliberative capacities and polarization in organization and management studies by exploring the diminishment of deliberative capacities explaining the important role of perceptions of formal organizations in the emergence of deliberative capacities.