Building on research on public spheres, sociotechnical imaginaries and transnational social movements, this contribution examines the relationship between the new climate movement and the European Union. Based on an analysis of frames we focus on justification strategies of Fridays for Future (FFF) and Extinction Rebellion (XR) in the field of climate change and a just transition. Using material produced by the two movements, we identify frames on political and economic order and relate these to the political communication concerning the EU. We combine this with data obtained from surveys of climate protest participants and narratives associated with EU climate and energy policies. Our results highlight the paradox that while climate protest participants in the EU are more trusting the EU than the general public, their political communication exhibits limited attention to the EU as a significant actor. Based on Fraser’s distinction between weak and strong publics, our analysis suggests that the climate movement in the EU functions as a ‘weak public sphere’, lacking substantial influence on political decision-making and would need to leverage traditional avenues like political parties or public opinion to enact change.