Assessing human rights due diligence in supply chains

Purpose This study aims to broaden the understanding of auditing practices of sustainability initiatives that promote sustainability standards in supply chains. We examine the extent to which the United Nations (UN) Guiding Principles on Business and Human Rights are embedded in such auditing practices to support the legitimacy of firms' supply chain efforts. Design/methodology/approach Building on legitimacy theory, this study explores the role and limitations of auditing practices to contribute to the legitimacy of corporate sustainable supply chain efforts. We analyze sustainability audit protocols of selected initiatives to determine their alignment with the UN Guiding Principles. Findings We identify key auditing gaps, specifically concerning the provision of guidance, stakeholder engagement, impact assessment and effectiveness measurement. Our findings extend discussions on legitimacy theory by emphasizing that formally adopting auditing practices calls into question the legitimacy of common sustainable supply chain practices. Research limitations/implications The study emphasizes that legitimacy requires substantive alignment with human rights standards, which encourages greater scholarly attention to this normative dimension. We provide recommendations for practitioners to better integrate normative standards into their auditing practices. However, our research is built on a limited sample of published audit protocols, suggesting further research on additional initiatives and their practices. Originality/value This article uses academic research on sustainable supply chain practices to highlight the limitations of initiatives' auditing practices in providing normative guidance for effective human rights due diligence.