This paper reports on a detailed critical analysis of assurance statements appearing in environmental, social and 'sustainability' reports short-listed for the 2002 Association of Chartered Certified Accountants (ACCA) UK and European Sustainability Reporting Awards scheme. Drawing on an evaluative framework centrally informed by the recently issued AccountAbility, Fédération des Experts Comptables Européens (FEE) and Global Reporting Initiative (GRI) guidelines on assurance, we assess the extent to which current assurance practice enhances transparency and accountability to organisational stakeholders. Our analysis raises question-marks regarding the independence of the assurance exercise, as well as revealing a large degree of management control over the assurance process. The latter is evidenced by a reluctance to address statements to specific stakeholder constituencies and a general absence of stakeholder participation in assurance processes. Distinct approaches to assurance among accountant and consultant assurors are highlighted, with the former primarily adopting a cautious, limited approach aimed at providing low assurance levels. While consultant assurors take a more evaluative approach, and appear to provide higher level assurance, their focus on aiding corporate strategic direction potentially blurs their independence. We contend that their apparent intertwining of the concepts of 'accountability' and 'value added' needs careful scrutiny as this may reflect an ultimate accountability to corporate management as opposed to other stakeholders. The paper concludes with some recommendations for future research involving direct engagements with assurance providers.