["British Journal of Industrial Relations, EarlyView. ", "\nABSTRACT\nTechnology and power are shaped by social context, linked to interactions and relationships among organisational actors. New technologies such as algorithmic management (AM) represent novel sources of contestation, raising questions for workers and unions. Our study examines the social processes union leaders use to navigate the transformation of rules that organise work and power relations under AM in hotel housekeeping. Drawing on everyday social processes at the workplace and applying a relational lens, we identify three interrelated strategies: (1) collective sensemaking through skill‐building and coordination of shared interests; (2) consultation and negotiation, which involve relational dimensions with management; and (3) collective action, which leaders adapt to the context of technology. These strategies modify rules to realise workers’ interests and, in some cases, coalesce into new institutional rules. We show how union leaders build power from the bottom‐up and how power resources, and worker power in the context of technological change, can be situated in everyday social processes.\n"]