The environmental regulatory risk landscape is evolving in ways that companies may not yet have considered. It is already well-known that financial regulators are working to protect capital market participants from greenwashing by the adoption of sustainability disclosure standards and the creation of a green taxonomy. Comparatively less attention has been paid to authorities with broad regulatory remits covering most or all sectors of the economy, which are increasingly using their powers to take enforcement action or cause reputational harm in respect of companies who engage in greenwashing. Meanwhile, private actors such as non-governmental organisations (NGOs) with ESG mandates can opportunistically seek to trigger or encourage investigations by such authorities, so as to pressure businesses to change behaviours. In this article, we examine the role of two such authorities: the Competition and Markets Authority and the UK National Contact Point.