The article investigates the driving forces that have been shaping the regulatory process of the EU directive on non-financial reporting (NFR). Drawing on a three-year empirical study, it argues that the latter was driven by a "coalition of the unlikely", led by a growing section of investors, together with a network of NGOs and parts of European trade unions. Rather than a formal alliance, we are witnessing the emergence of an objective convergence of interests amongst the three groups of actors, aimed at limiting managers' power and obtaining more corporate transparency and accountability. Deploying a political economy explanatory framework, the paper originally contributes to the existing literature on EU CSR policy, focused on the cleavage between business and civil society. The role of EU regulators (the "Barnier-effect") in supporting mandatory NFR and the impact of the financial crisis, seen as catalysts for changes, are also taken into account. The paper concludes discussing some implications for policy-makers and research.