The rise across Europe of political parties espousing an ethnic conception of the nation, explicitly opposed to immigrants and minorities, has brought into stark relief the politics of identity. Exploiting multiple identity questions in a large, nationally representative UK survey, this paper investigates the drivers of ethnic and political identity and the extent to which they are similar. It does so for both the ethnic majority and ethnic minorities. Locating our analysis within social identity theory, we consider the role of observed characteristics, including party affiliation, the experience of harassment, and political context in shaping ethnic and political identities. We also show that there are unobserved factors jointly implicated in individuals' political and ethnic identities, which we interpret as providing suggestive evidence of more general political mobilisation of ethnicity. Although individual characteristics have largely expected associations with identity, we find that the local share of UKIP/BNP voters heightens ethnic but not political identity among both majority and minority populations. By contrast, harassment and discrimination shapes minorities' political but not ethnic identity. Contrary to expectations, both political and ethnic identities are stronger among secondgeneration compared to immigrant minorities.