Analysis of the British Election Studies suggests that migration between the north and south of Britain does have political effects, southerly migration leading voters away from Labour and northerly migration towards Labour. This pattern persists even after controls for prior social and political characteristics, experience of social mobility, and changes in local political environment. It does, however, appear to be a new phenomenon, not apparent in the earlier election studies. The results support the hypothesis that the north-south divide constitutes a distinct new political cleavage distinct from social class and the other more familiar social bases of voting behaviour.