He took part in the Third Silesian Uprising and in the Polish–Soviet War. Dubois was a creator of the "Red Scouts" ("Czerwone Harcerstwo Towarzystwa Uniwersytetu Robotniczego"). In years 1928–1933 he was a member of the Polish parliament Sejm, and a councillor in Warsaw from 1938. Dubois was a secretary in the editorial office of the "Robotnik" (the Worker) paper. As an opponent of Sanation he was charged in 1930 with the communist agitation in Lwów and sentenced in the Brest trials for 3 years in prison. He was held at the Brest Fortress and while imprisoned, run in the 1930 Polish legislative election. He was released the following month.