In the period 1988 till 1991 Darabos was chief executive of the federal branch of the Dr.-Karl-Renner-Institute in Burgenland, a social democratic think tank.

Between December 2000 till March 2003, Darabos was the head of the Social Democratic Group in the federal parliament of Burgenland.

In 2004 he ran the election campaign of later President of Austria Heinz Fischer, and on 16 June 2004 he became a member of the Austrian parliament (SPÖ).

In 2010 Vienna's mayor Michael Häupl (SPÖ) suggested it should be decided whether young Austrians should still have to serve in the army.

On 11 March 2013 Darabos resigned as minister in order to return as Secretary General of his party, responsible for running the upcoming parliament elections.