BACKGROUND: Few ergonomics studies have explored the work required to implement territorialized public policies. OBJECTIVE: To identify key challenges for ergonomists who analyse and support intermediation work taking place in the design and implementation of a Territorial Food Project or TFP (a public policy device). METHODS: We adapted a framework developed in the field of political sociology. The analysis focuses on two scales to identify key characteristics of intermediation work: the agri-urban area as delimited and targeted by the TFP; and the farm and its relationships to food systems. To capture how intermediation work articulates prescription and action, we studied first the work carried out by the actors to use a public policy device such as TFP, and second the evolving farming work systems’ connections to food systems and how they are supported by various actors. RESULTS: Intermediation work is spread across a wide diversity of actors. Coordination at governance level aims to allocate resources among institutional actors and to check the progress of the elaborated action plan. Coordination at operational level, which is meant to support farming work systems dynamics or to implement the action plan, focuses on fostering the emergence of initiatives but seems to lack a shared vision and time availability. CONCLUSION: We identify two main challenges: to further develop a framework for analysing the intermediation work occurring in a multi-scale and territorial perspective; and new intervention methods so that ergonomists can take part in and support such intermediation work.