As early as 1930, Hans Jahn was already warning against National Socialism in London. In 1933, as a member of the central executive committee of the United Railroad Workers’ Federation, he opposed the dissolution of the labor unions by the National Socialists. With the help of a salvaged membership card index, Jahn managed to set up a labor union resistance group in the Rhine-Ruhr area that collaborated closely with the International Transport Workers’ Federation (ITF). In 1935 the Gestapo discovered this secret organization and arrested Hans Jahn. After his release he fled via Prague to Amsterdam in the summer of 1935. He was expelled from Belgium in 1936. With ITF support, Jahn continually made contact with former labor union officials in Germany and published an opposition journal for German Railroad employees between 1936 and 1938. In 1940 he escaped to London via Spain and Portugal. In London he set up an independent labor union group that affiliated to the National Group of German Labor Unionists in Britain two years later. Hans Jahn returned to Germany in 1945. After 1949 he was elected chairman of the German Railroad Workers’ Union.