According to an interview by Franz Schwarz, son of Austria President from 1933 to 1938 and 1946 to 1955 in 2008, Mock was a member of the SA and the NSDAP, which were illegal in Austria before 1938. Mock was involved in 1938 when the management of the club at Austria was taken over by the National Socialists. He then applied for regular membership in the party on 23 June 1938 and was admitted retrospectively to May 1 (membership number 6,336,185).