Previous research has consistently shown that those on the political Right tend to prefer or use conventional or Stage 4 moral reasoning, while those on the political Left prefer principled or Stage 5 reasoning (cf. Kohlberg, 1976). One interpretation of this finding is that developmental level of moral reasoning influences a person's political views, another that the moral ‘stages’ associated with contrasting political positions are in fact contrasting politico–moral ideologies and that people choose the form of moral reasoning which best expresses their own political identity. We report four studies to test aspects of these alternatives. Participants (N = 50) in Study 1 rated moral arguments representing different stages as differentially relevant to people of varying political persuasions. In Study 2, participants (N = 106), assigned to play the role of constituency political parties (either Labour or Conservative) selecting candidates to represent their party, evaluated imaginary candidates differentially as a function of the kinds of moral arguments the candidates expressed. In Study 3 (N = 61), principled and particularly conventional moral arguments were again found to express contrasting political identities. In Study 4 (N = 51) a manipulation of the salience of participants' political identity produced as predicted high correlations between moral reasoning scores and measures of political attitudes when political identity was salient but not when personal identity was salient. The findings overall, however, only partially support the view that political identity influences moral reasoning. We conclude that, although degree of preference for conventional or Stage 4 reasoning is a function of political identity, principled reasoning may be unrelated to political orientation. We also propose that these two forms of reasoning do not reflect successive developmental stages and that preference for one may be independent of preference for the other.