In this article, we present an innovation policy instrument currently experimented in France. This policy draws on the normative hypothesis that sustainable transitions rely on participatory research. The concept of participatory research emphasizes on the systemic dimension of participation of civil society to research and innovation (Joly, 2020). This systemic dimension needs a different framing of innovation policies which have to be inclusive, experimental and guided by social and environnemental objectives (Schot and Steinmueller, 2018). This framing needs to sustain research intermediations in third sector organisations. The notion of 3rd sector echoes the anglo-saxon framework of society organized into three sectors: the State, the market and the 3rd sector. According to Alcock (Alcock, 2010), 3rd sector is associated with values and principles such as association, mutuality, altruism, democracy, and may balance values of State and market in research and innovation systems. 3rd sector organisations are major actors in the development and generalisation of social innovations (