Gadomski was designated as a member of the General Sejm in 1760, the Convocation Sejm in 1764, the Czaplic Sejm in 1766 and the Repnin Sejm in 1767. He supported the election of Stanisław August Poniatowski to the Polish throne. In 1766, he was decorated with the Order of Saint Stanislaus and the Order of the White Eagle in later years.