Surprisingly, labour provisions in EU bilateral trade agreements have widened and deepened over the past decade. One would have expected the opposite, given the coming to power of centre-right governments in the early 2000s and a stronger liberalization agenda since 2006. This article addresses this rather remarkable development. First of all it dismisses the argument that protectionist motives underlie the stronger social clauses in EU trade agreements. Instead, drawing on the theory of the life-cycle of norms, it suggests that social trade has become an unobjectionable norm within the EU. The article then offers several explanations for why the social-trade nexus has been barely disputed, and indeed has further expanded through subsequent trade arrangements. These include the stronger influence of the European Parliament, path-dependencies stemming from the EU’s previous template, and the need to gain public support in the face of criticism of free trade agreements. Most importantly, it stresses that the framing of core labour rights as part of a broader ‘sustainable development’ agenda has contributed to their unobjectionable status. While this framing has helped to forge a consensus with regard to the social trade agenda, giving equal status to labour and environmental provisions under the sustainable development umbrella might also have adverse consequences for the concept of labour provisions