Abstract Non-state actors contribute with inputs to the elaboration of the national interest in trade negotiations, thus enhancing its legitimacy. Nevertheless, does the participation of those actors necessarily equal influence on the part of all segments of civil society on policymaking? To answer the question, I argue that procedural legitimacy should be evaluated not only in relation to the inputs society provides to the State, but should also consider whether officials actually analyse societal contributions in decision-making. I demonstrate the empirical application of the model based upon Brazil's experience in multilateral trade negotiations during the 2000s, using Mexico as a shadow case. I conclude that foreign trade policymaking can only be democratised if, in procedural legitimacy, the State attributes equal weight to contributions from all types of societal actors, including civil society organisations and organised social movements, which tend to have less material resources and power than interest groups such as business associations and labour unions.