In this article, our goal is to understand the degree to which citizens vote choices in a post-Eurozone crisis in countries that went through bailouts, namely Greece, Ireland, Portugal and Spain are driven by the traditional left-right cleavage, or whether instead, the transnational cleavage, represented by various issues, may be more important, especially in cases where citizens vote for challenger parties. Our goals are the following: to establish the main cleavages which are driving the vote for each major party in Greece, Ireland, Portugal and Spain. Secondly, to understand whether the cleavages which drive voters are significantly different comparing mainstream and challenger parties in the countries analysed. Thirdly, whether the cleavages are reinforcing or cross-cutting from the voters’ perspective. And fourthly, whether perceptions of party system polarization make any difference for the relative importance of cleavages. In order to answer these questions, we make use of an online survey which was collected in 2019, where we have included respondents’ position on each of the issues with which we operationalize the cleavages we are focusing on as well as CHES data released in 2019 on party positioning on each of these cleavages/issues which has been coded independently by experts.