He is a member of the CDU since 1981 . He was Secretary of State in the Federal Ministry of Finance from 1990 to 1993 . A member of the CDU since 1981 , he was Secretary of State in the Federal Ministry of Finance from 1990 to 1993 , and as such , the administrative head of the Ministry and the deputy of the Federal Minister of Finance ( Theodor Waigel ) .