["European Journal of Social Psychology, EarlyView. ", "\nABSTRACT\nThis study tests a dual grievance model of populism by examining whether relative deprivation and external political inefficacy are linked to two core dimensions of populist beliefs (people sovereignty and anti‐elitism) via aversive political emotions (anger, sadness and fear) and institutional distrust across six European countries (N = 5487). Multigroup structural equation modelling showed that relative deprivation was consistently positively associated with all three emotions. However, only anger and institutional distrust serially mediated its link to populist beliefs in every country, and this effect was larger for anti‐elitism than for people sovereignty. Cross‐country differences emerged in how external political inefficacy related to emotions and how emotions related to distrust. Although anger and distrust formed a stable pathway to populism, the mediation paths involving sadness and fear varied across contexts. Overall, these findings clarify when and how political affect and institutional evaluations help channel grievances into populism, highlighting both shared and context‐dependent mechanisms.\n"]