Abstract
Based on cross-national comparative research conducted in France and the UK, this article explores to what extent and under what conditions trade unions situated in different legal systems have turned to the courts to challenge discrimination at work. It investigates the interplay between a broad range of structural factors that offer specific opportunities, and the way trade unionists interpret contexts to promote legal mobilisation in addition to or in place of other repertoires of action. In so doing, it contributes to the understanding of employment discrimination law enforcement and the role of micro-level actors in enabling litigation strategies.