This article explores tensions in the ways in which non-governmental activism, as represented by trade unions and non-governmental organisations (NGOs), frames the concerns of migrant domestic workers (MDWs) living in South Africa. It analyses how seemingly polarised trade unions and NGOs involved in struggles on behalf of MDWs adopt singular discourses about labour rights at varying political moments to achieve their own goals. These singular frames conflate the issues around MDWs and their rights, reducing them to rigid categories of either ‘international migrants’ or ‘domestic workers’. The framing of MDWs’ concerns as international migrants’ rights issues reflects a transnational political approach that migrant-aligned trade unions and NGOs use in order to connect with pre-existing labour movement narratives and debates. This framing must contend with locally aligned trade unions and NGOs who frame international MDWs’ concerns essentially as equal to those of internal MDWs through the mantra ‘a worker is a worker’. This homogenising framing of worker struggles generates deep-seated xenophobic discourses about migrants in South Africa’s labour market which are compatible with a citizenship-based workers’ rights movement and ‘national chauvinism’. Although the mantra ought to allow every worker to stand up for their rights without risking immigration detention or deportation, locally aligned trade unions and NGOs use it to de-exceptionalise international migrants in order to appeal to a local constituency concerned about the economy being ‘overrun’ by international migrants. The article concludes that there is need for internal and international MDWs to organise themselves in ways that recognise their similarities and accommodate their differences.