It is a characteristic of platform capitalism that struggles to re-embed digital platform work within institutionalised forms of employment have been set in motion by new labour actors (i.e. self-organised, grassroots unions). Contrary to the view that these new actors signify the decades-long decline of traditional unions, evidence increasingly highlights their continued relevance to the labour–capital relations of platform capitalism. We argue that dynamic interactions between ‘old’ and ‘new’ labour actors in platform capitalism are influenced by national union traditions that emerge more vividly when struggles to re-embed labour relations require the transition to more institutionalised forms of labour resistance. We develop this argument based on a longitudinal qualitative study of labour struggles in the food delivery sector in the city of Bologna, Italy. We pay particular attention to the dynamics of intra-labour actor relations that have unfolded in the sector across different temporally based events of contention in the city. As we illustrate, synergies between the two were prompted by the self-organised workers’ need to rely on partners with an ‘official’ status when re-embedding procedures required; yet, collaboration was also favoured by what we describe as a ‘posture of respect’ developed by the traditional union vis-à-vis the self-organised informal union, particularly with regard to their quest for autonomy from traditional union structures. We interpret this approach of the established labour actor in line with its traditional orientation as ‘class’ actor, whose actions look beyond the membership so as to expand solidarity to all workers, including in new productive (platform) sectors.