Ecological modernisation tends to dominate institutional definitions of low-carbon transitions in industrialised countries. While most works study the market solutions and the technological innovation constraints of Eco-Modernist (EM) projects, this article analyses them at a micro level through the study of the development of an EM coalition supporting industrial Carbon Capture, Utilisation, and Storage (CCUS) in France. Drawing on interpretive policy analysis and the sociology of innovation, and focusing on the building and erosion of a common frame within the coalition, we highlight the ambivalence of the framing of the solution and the instability of the coalition supporting it. First, we show that, like most EM innovations, almost all CCUS projects in France have been co-constructed between public and private actors. Second, we argue that the ambivalent frames developed by French promoters of CCUS initially legitimated the deployment of the CCUS technologies but led to a misalignment of actors in the long term. We conclude by encouraging scholars in more micro-observation of EM coalitions in order to gain a better understanding of their internal conflicts and of their heterogeneity, and to document the general, now dominant, discourse of EM in the field of environmental policies.