Kelber became a member of the SPD in 1985 and was the local party chairman in Bonn from 2001 to 2008, and a member of the SPD executive board 2009 to 2011.
Member of the German Parliament, 2000–2019
Kelber became a member of the Bundestag on 1 September 2000, replacing Rudolf Dreßler who left. He won re-election as directly elected member for the constituency of Bonn in each of the elections from 2002 to 2017.
In parliament, Kelber was a member of the Committee on the Environment, Nature Conservation and Nuclear Safety from 2000 until 2005, where he served as the SPD parliamentary group's rapporteur on the European Union Emission Trading Scheme (EU ETS).[2] From 2005 until 2013, he served as the group's deputy chairman under the leadership of successive chairmen Peter Struck (2005-2009) and Frank-Walter Steinmeier (2009-2013). In this capacity, he coordinated the group's policy initiatives on the environment, energy, sustainability, agriculture and consumer protection.
Federal Commissioner for Data Protection and Freedom of Information, 2019–present
Kelber was elected to become Federal Commissioner for Data Protection in 2018[3] and took up the office on 7 January 2019 after giving up his Bundestag seat.[1]