Over recent decades scholars have documented the increasing electoral salience across Western Europe of a new post-materialist or libertarian–authoritarian dimension. The theoretical status of this new dimension and its relation to extant cleavage structures – notably the class cleavage – has, however, been debated. This paper demonstrates that the dimension reflects a new education-based cleavage that has come into existence since the mid 1980s. Thus, analyses of Danish election surveys and party manifestoes show the linkage between the voters' educational level, their values, and their voting for authoritarian or libertarian parties – i.e. the existence of an education cleavage. Due to its status as one of the more advanced countries, Denmark can be seen as a least likely case for the existence of a structurally based cleavage; hence, the existence of the education cleavage in this country indicates that similar cleavages lie underneath the authoritarian–libertarian dimension in other countries as well.