Drawing on the literature of social movements and emotions, this article analyses a case of the union-led movement against outsourcing in the UK. Our focus is on the emotional processes of collective identity formation and the movement culture of new grassroot unions, addressing the themes of movement culture, collective identity and political solidarity. Data consists of participant observations, interviews, and additional website and media material. The results show that the movement culture of the new grassroot unions is characterised by direct action and a collective identity based on a proud re-centring of BAME workers as subjects of labour struggles. Key emotional processes consist of sharing emotions of humiliation, anger, and exclusion, but also joy and feelings of solidarity. A crucial part of the movement’s expansion is due to the construction of political solidarity and coalition-building. The results demonstrate the importance of heeding the crucial mobilising power of shared emotions in the analysis of new labour unions. The article contributes to labour movement research with an enhanced understanding of immaterial claims on dignity, respect and care, alongside the cognitivist focus on material work conditions and labour rights.