In addition to many publications, Jacques Leclercq helped to found the School of Political and Social Sciences at the Université catholique de Louvain and the Society for Political and Social Studies.
From 1945 on he was in favor of the creation of a regional Walloon Christian-inspired movement, Rénovation wallonne, and wrote in 1963 an appeal to Catholics to rally to the movement, titled Les catholiques et la question wallonne ("Catholics and the Walloon question") [REF].