Purpose This study examines the role of a semi-state actor in developing an agrifood multi-stakeholder initiative (MSI) and its related sectoral accounting and reporting in response to the grand challenge of environmental sustainability in the agrifood industry. The paper also explores how an national environmental protection agency and environmental non-governmental organizations (NGOs) challenge the initiative’s performance. The concepts of dialogic accounting and accountability provide the theoretical framework for the study. Specifically, the study empirically assesses and extends existing theorisations of accountability-based accounting systems to the context of an MSI. Design/methodology/approach The study involved extensive documentary data collection, discussions with the semi-state staff, NGOs and sector experts, attendance at events and seminars and regular monitoring of media reports on the sector. This enabled an examination of the role of state, semi-state and civil society actors in the creation and evolution of the MSI and the related accounting and accountability processes. Findings The study finds that state, semi-state and civil society actors have diverse and often conflicting roles in addressing environmental sustainability in the agrifood sector and reveals the dynamic and complex nature of dialogic accounting and accountability in the context of an MSI. In particular, the study finds that the responsibility network around an MSI can create their own disclosures to challenge and critique an MSI’s performance and its incomplete and aspirational accounting. They can also seek to extend the accountability space beyond the MSI to include the sector as a whole and related government policy. Research limitations/implications For practitioners, NGOs and policymakers, the study illustrates the value of accounting practices and disclosures that extend beyond corporate entities. These practices and disclosures can form part of an overall process of dialogic accountability, holding a sector or part of a sector to account for their environmental impacts and highlighting deficiencies in performance. In this way, NGOs and other actors can support progress towards enhanced environmental sustainability in a sector. The study encourages accounting scholars to consider how their research can support this type of accountability and these civil society actors. Originality/value The study provides insight into the role of diverse actors including state and civil society groups in enhancing accountability for environmental sustainability. It contributes to our understanding of how a variety of actors engage within and around MSIs. It adds to the literature on sustainability accounting and accountability that comes in a form and space other than corporate reports and press releases.