["JCMS: Journal of Common Market Studies, EarlyView. ", "\nAbstract\nPrecarious employment has gradually moved onto the European Union (EU) policy agenda, so far culminating in the proclamation of the European Pillar of Social Rights (the Pillar). However, the effectiveness of these renewed social ambitions is challenged by legal uncertainty and entangled in ongoing political and legal disputes over the definition of ‘worker’ under EU law. This article examines how EU political and legal dynamics respond to the legal uncertainty faced by those in precarious employment and how these responses condition effective protection for those at the margins of the labour market. It explores the contested definition of ‘worker’ and analyses two recent legislative initiatives: the Directive on Transparent and Predictable Working Conditions and the Platform Work Directive. The article finds that persistent political and legal disagreements continue to fuel legal uncertainty for precarious workers. Access to labour rights and social protection remains tied to worker status – a status that is still primarily defined at the national level."]