Abstract This article studies the interactional functions of racism discourse in mobilizing support for right‐wing populism. The analysis focuses on the controversy surrounding UKIP's “Breaking Point” poster campaign, which launched days before the historic British EU referendum. We focus on the development of “tripolar relations” between the UKIP party leadership, mainstream political elites, and ordinary citizens. Using thematic discourse analysis, we show how the poster was depicted as racist and the UKIP leader Nigel Farage was accused of scaremongering and stoking racism by means of propaganda. This criticism becomes the grounds for mobilization as Farage defended the campaign against the charge of racism and his supporters rose to his side. We conclude by showing how arguments about the nature of racism are identity performances that can reproduce or challenge existing social relations. This article thus identifies the rhetorical “collaboration” that exists between critics and defenders of racism and the inadvertent political outcome of this interaction.