The literature on deliberative mini-publics (DMPs) establishes a link between political dissatisfaction and support for DMPs. However, little is known about the sources of political dissatisfaction that trigger this greater support for mini-publics. Our research tackles this specific question and claims that citizens’ dissatisfaction is rooted in a position of ‘losers of representative democracy’, which, in turn, leads citizens to be more open to reforms that move away from the representative model. Building on the literature on loser’s consent, we focus on the effect of voting for a party not associated to government and of descriptive and substantive (under)-representation on support for deliberative mini-publics. We rely on a comparative survey conducted across 15 Western European countries. Supporters of opposition parties and those who are badly represented both descriptively and substantively are more supportive of deliberative mini-publics. These findings have important implications for our understanding of public appeal for deliberative democracy instruments.