The Unintended Consequences of Left- and Right-Wing Eurosceptic Parties’ Messages on Citizens’ EU Preferences

Do Eurosceptic parties shape citizens’ attitudes in the intended way? The literature on party cues and attitudes toward the European Union (EU) shows that messages from political parties strongly influence citizens’ opinions about the EU, with Eurosceptic parties able to generate hostility toward it. However, this research has largely overlooked the existence of distinct types of party Euroscepticism and voters’ ability to distinguish between them. The present paper addresses this gap by focusing on the Euroscepticism of radical left and radical right parties. The former primarily criticizes the neoliberal nature of EU rules and policies and the lack of popular accountability within EU institutions. By contrast, the latter focuses on the threats the EU poses to national identity and sovereignty, and criticizes its insufficient national accountability. These distinct forms of critical evaluation also lead to contrasting preferences for the EU’s future. While radical left parties generally support strengthening democratic control over EU institutions and expanding their competences to increase redistribution capacity, radical right parties tend to favor a re-nationalization of EU competences and the weakening of supranational institutions. We argue that certain characteristics of parties’ rhetoric may make it difficult for citizens to perceive the differences between these two visions, thereby generating unintended consequences: left-wing (right-wing) parties may inadvertently induce right-wing (left-wing) Euroscepticism among voters. We focus on two characteristics of party messages that may increase the likelihood of such unintended effects – namely, blame attribution and clarity of framing. Regarding blame attribution, when radical left parties attribute negative outcomes to the EU system rather than to specific actors, they may foster support for the re-nationalization of EU competences. Similarly, when radical right parties choose a more targeted form of blame attribution, they may signal to voters a critique compatible with retaining or adjusting existing competences. With respect to framing clarity, when parties’ messages do not clearly articulate whether conflicts are economic or national, or whether accountability should be national or popular, citizens may infer preferences about the EU’s future that differ from the parties’ intended positions. In both cases, rhetorical ambiguity can thus redirect voters toward forms of Euroscepticism associated with the opposite ideological camp. To empirically test these expectations, we will conduct two survey experiments in April 2026 across five European countries with Eurosceptic parties from both extremes of the ideological axis: France, Germany, Italy, Portugal, and Spain. In these experiments, the Eurosceptic messages of radical left and radical right parties will be manipulated in terms of blame attribution and framing clarity to assess their effects on citizens’ preferences for the EU’s future. Fresh results will be presented at the SGEU conference. Detecting such unintended consequences may have important implications, as it would qualify the view of Eurosceptic parties as the primary drivers and beneficiaries of EU politicization and highlight possible ideological asymmetries in their ability to shape citizens’ EU preferences.