Increasingly, modern European states, including the UK have become ethnically diverse as a result of international labour migration and other factors such as asylum seeking. Ethnic diversity involves cultural diversity, a multiplicity of world views which may call into question hegemonic notions of citizenship. De. nitions of citizenship rights and obligations commonly presuppose a shared public culture1 (Rex, 1996:33), which cannot, of its nature, tolerate diversity. Recent commentators have discussed the resulting exclusionary potential of citizenship, referring to cultural diversity, and also to other dimensions of social differentiation.