Prussian House of Representatives
Trinowitz was, from 1919 to 1921, Member of the Prussian House of Representatives (Preußischer Landtag). In addition, he was, from 1919 to 1925, Member of the City Council of Tilsit as well as a member of the provisional German Council on Economic Affairs (Reichswirtschaftsrat) as a representative of the trades' workers from 1921 until 1929.