For decades, companies found in international protocols and standards an alternative source of normative guidance to operatively implement sustainability policies at an organisational level. The ever-increasing adoption of these multi-faceted policies and guidelines co-occurs with a more proactive and voluntaristic attitude towards CSR implementation by companies. Born as a kind of soft corporate law to reinforce a regulatory answer to sustainability issues, today, CSR due diligence is becoming a central pillar of the transition of the economic system towards a great level of sustainable development. The paper presents the results of an interventionist research carried out by researchers in collaboration with the European Parliament, aimed at developing a normative resolution on the prominent role of CSR due diligence and its accountability. Through the exploration of the different state-of-the-art of European companies on CSR due diligence, findings suggest that there is considerable room for improvement in CSR due diligence that can be reached through a normative intervention. In addition, the paper contributes to the development of the literature on interventionist research carried out by business scholars, focusing on academiaindustry-institutions relations.