[2] On 10 September 1970, Gallus entered the Bundestag to replace Ralf Dahrendorf, who had resigned.

On 16 December 1976, Gallus was appointed Parliamentary State Secretary to the Federal Minister of Food, Agriculture and Forestry in the Federal Government headed by Chancellor Helmut Schmidt.

Following the break-up of the social-liberal coalition, he initially resigned from office on 17 September 1982.

Gallus then left the government on 21 January 1993 at the same time as the previous Federal Minister Ignaz Kiechle.

Biographisches Handbuch der Mitglieder des Deutschen Bundestages.