This paper studies a treatise on provincial councils probably written by Pierre Soybert, canonist and bishop of St-Papoul who was close to conciliarism, and which dates from around 1430. The aim will be to study the place given by the author to the question of the consent of suffragan bishops and of the metropolitan in the provincial councils, the criteria and framework for exercising consent and how he uses canon law to support his vision of the collegiate organisation of the Church at local level. This will also raise the question of the link between this treatise and the legal arguments developed in the conciliarist texts of the early fifteenth century on general councils, and the mobilisation at local level of the model provided by the Council of Constance, several texts of which are cited in the treatise.