In 2001 he was elected vice-chairman of the Metalworkers' Union, and in November 2005 was elected as the first chairman of the newly formed trade union IF Metall.
2001. aastal valiti metallitööliste ametiühingu aseesimeheks ja 2005. aasta novembris äsja moodustatud ametiühingu IF Metall esimeseks esimeheks.