The relationship between social class and electoral behaviour has long been a central concern in political sociology and comparative politics. While early cleavage theory emphasized the structuring role of class in shaping party systems (Lipset and Rokkan, 1967), subsequent research has documented a weakening of class voting across advanced democracies (Clark and Lipset, 1991; Evans, 1999). More recent contributions, however, suggest that rather than disappearing, class-based alignments have been reconfigured in interaction with new political divides linked to globalization, cultural conflict, and the transformation of party competition (Kriesi et al., 2008; Oesch, 2008; Bornschier, 2010; Evans and Tilley, 2017).

Spain and Portugal provide a particularly relevant comparative setting for revisiting these debates. Both countries share key structural and political characteristics —relatively recent democratic consolidation, party systems historically structured along the left–right dimension, and similar socioeconomic transformations linked to European integration and post-industrial change— which make them well suited to analysing the evolution of class voting in Southern Europe. At the same time, their trajectories allow us to examine how common structural pressures interact with distinct patterns of party competition and political supply. From this perspective, the comparison contributes to broader discussions on the transformation of political cleavages and electoral alignments in European democracies (Kriesi et al., 2012; Hooghe and Marks, 2018).

Within this framework, three major critical junctures in the first quarter of the 21st century invite a reassessment of class voting in both countries: 1) the 2008 economic and political crisis, which intensified material inequalities and political disaffection (Bosco and Verney, 2012; Hernández and Kriesi, 2016); 2) the rise of new radical left parties such as Podemos and Bloco de Esquerda, which challenged traditional linkages between working-class voters and mainstream social democratic parties (March and Mudde, 2005; Ramiro and Gómez, 2017; Lisi, 2019); and 3) the emergence of radical right parties such as VOX and CHEGA from 2019 onwards, marking the end of the Iberian exception and introducing a new axis of political conflict (Alonso and Rovira Kaltwasser, 2015; Turnbull-Dugarte, 2019; Ortiz, 2019).

This paper, thus, examines the evolution of class voting in Spain and Portugal between 2000 and 2023 using data from the European Social Survey. The aim is twofold: first, to assess whether traditional class alignments in electoral behaviour have declined or persisted over time; and second, to analyse whether working-class voters have been realigned towards new political options, particularly radical left and radical right parties, across these critical junctures.

The paper contributes to the literature on electoral realignment and cleavage transformation by focusing on Southern Europe, a region that has received comparatively less attention in this debate. It engages with recent work on the restructuring of political conflict in Europe (Kriesi et al., 2012; Hooghe and Marks, 2018) and on the changing social bases of party competition. The central expectation is that class voting has not vanished but has been reshaped by the interaction between economic grievances and emerging cultural conflicts, producing new and more complex patterns of alignment among working-class voters.