Opportunities for migrants in Britain have become increasingly differentiated by hardened legal barriers, restricted access to asylum and filtering by selected skills. This article explores the effects of this differentiation on diaspora formation, social mobility and class identities. It takes the case of one of the UK's largest new African migrant groups – black Zimbabweans – who mostly come from middle class/elite backgrounds, but who have ended up in unskilled and informal work, as well as securing professional posts in Britain. The article asks whether, and in what sense it might be useful to talk of the polarised opportunities created by legal status in terms of emerging class differences and challenges to class identities. It dwells on the subjective experience of those in irregular legal circumstances, whose loss of status in Britain has been particularly acute, drawing on theoretical debates on abjection and dehumanised ‘bare life’ that speak directly to the popular discourses and language in which those doing menial work and lacking papers spoke about their experiences and place in Britain. As some have, however, maintained their class position both at home and in intergenerational terms, the article highlights the transnational calculations that continue to render even illegal unskilled work in the UK attractive, and underlines the importance of discussing abjection in terms of the relations of power and processes that create legal spaces of exclusion rather than as a putative underclass. Notwithstanding such calculations, the article highlights the importance of legal status and inequality within migrant groups in shaping the dynamics of new diaspora communities in Britain.