The so-called “Traffic Light Index” (TLI) is a meta-sustainability label aimed at condensing the information provided by existing sustainability labels into an overarching message on food products’ environmental footprints. Such an overarching message is critical to reduce the confusion caused by existing labels and to foster more sustainable dietary habits among consumers. While research shows that the TLI is a viable and effective choice, its actual development and implementation are impeded by debates between relevant stakeholders in the European food system. This study examines those debates and adopts a multi-stakeholder perspective to address the following question: How do different stakeholder groups involved in the discussion towards a meta-sustainability label inhibit the adoption of the TLI label? Exploratory interviews with representatives from non-governmental organizations, social enterprises, academia, multi-national corporations, and governmental organizations show that each stakeholder group (1) adopts either optimistic or skeptical attitudes towards the TLI label, (2) perceives different types and magnitudes of barriers to its adoption (i.e., cognitive, methodological, and processual), and (3) proposes solutions to overcome those barriers that are either of an entrepreneurial or risk-averse nature. Findings further reveal that multi-stakeholder interactions influence attitudes and thereby inhibit or favor TLI adoption. Hence, entrepreneurial (vs. risk-averse) solutions proposed by optimistic (vs. skeptical) stakeholders may alter the attitudes of skeptical (vs. optimistic) stakeholders and the barriers they perceive to TLI adoption. By responding to calls for holistic approaches towards food labelling, our study shows how the diversity of stakeholders’ perceptions towards the TLI inhibits its adoption. We propose a theoretical framework and a set of propositions that can serve as springboards for policy ideas to propel progress in food labelling for environmental sustainability.