ABSTRACT The classic gap between lower and higher social classes in their likelihood to vote for radical left parties (RLPs) persists to this day. Prior studies showed that economic and political grievances predict support for the radical left, but they largely neglected to address whether the working class is more likely to vote for RLPs because they are economically and politically dissatisfied. This study, therefore, examines the explanatory role of economic and political grievances. It also examines whether the class cleavage in RLP support depends on a country's economic performance in terms of wealth, unemployment and income inequality. European Social Survey data on 19 countries between 2002 and 2018 are analysed using three-level logistic regression models. The results replicate that people in lower social classes are more likely to vote for RLPs than those in higher ones. They do so because they are more dissatisfied with the economy, democracy and, particularly, income inequality. Against expectations, class voting for the radical left is not conditional on macroeconomic performance. Yet, RLPs turn out to be more electorally successful as a result of economic and political grievances in times of economic prosperity, suggesting that feelings of relative deprivation spur radical left voting.