自由都市ダンツィヒ
When the Free City of Danzig was formed, the Danzig branch of SPD reconstructed themselves as a separate party, the Social Democratic Party of the Free City of Danzig. Gehl was the party chairman 1919–1920. He then became the chairman of the parliamentary faction of the party. Gehl served as Vice President of the Senate of the Free City of Danzig from August 1925 to March 1931 and twice President of the Volkstag.