Since 2008, most bilateral and regional EU trade agreements contain so-called Trade and Sustainable Development chapters. Such sustainability chapters typically include commitments to core ILO labour rights and provide specific monitoring mechanisms to ensure compliance. Several observers however, have voiced concern about the enforcement potential of these provisions in practice, beyond legal and institutional reforms. As a means to overcome this compliance gap, this article explores how the inclusion of existing Voluntary Sustainability Standards (VSS) in trade agreements could potentially enhance the monitoring and enforcement of labour provisions in EU trade agreements. Based on experiences captured in a case-study on the functioning of the 2013 EU-Colombia Trade Agreement, we argue that linking VSS to labour provisions in trade agreements could significantly contribute to rendering these provisions more effective. Linking labour provisions to the monitoring and auditing mechanisms of accredited but independent VSS, we argue, could help close a regulatory gap, add credibility to the provisions and help overcome capacity challenges in the implementing countries. In turn, the integration of VSS in trade agreements offers public regulators the opportunity to demand a strengthening of the quality of VSS in terms of their design and procedures.