 Upon his return to France in 1758, Vadier acquired large tracts of land in Pamiers and in 1770 purchased the office of "conseiller" (magistrate), which brought him into conflict with many of the local aristocracy and affluent bourgeoisie.Elected as deputy to the Third Estate in the Estates-General of France for the County of Foix (in 1789), Vadier took no prominent part in that assembly.He left his office as representative in the National Constituent Assembly of the Constitutional Monarchy (September 1791), returning to Ariège "département", becoming president of the district tribunal in Mirepoix, contributing to the creation of new revolutionary institutions throughout the region.