He then became the assistant to Roel Stenhuis, leader of the Dutch Confederation of Trade Unions and general secretary of the International Federation of Factory Workers.
[1] Spiekman briefly worked as an insurance inspector, but at the end of the year was recruited as assistant to Gerrit Smit, general secretary of the International Federation of Commercial, Clerical, Professional and Technical Employees (FIET).
During this period, he joined the Independent Socialist Party, and this led the Dutch trade union movement to oppose him succeeding as general secretary of FIET on Smit's death, in 1934.
Spiekman travelled around Europe, maintain links with current and banned affiliates of FIET, although he was unable to enter Germany after 1938, when the Gestapo made plans to arrest him.
At the conference, some delegates complained that Spiekman had invited representatives of German trade unions, even though they had been opponents of the Nazis.