In addition to her committee assignments, Hübner has been a member of the Parliament's delegation for relations with the United States since 2009. On 15 September 2010 she joined the Spinelli Group in the European Parliament, which was founded to reinvigorate the strive for federalisation of the EU; other prominent supporters included Jacques Delors, Daniel Cohn-Bendit, Guy Verhofstadt, Andrew Duff, Elmar Brok. She is also a member of the European Parliament Intergroup on Sports. From 2014 until 2019, she was a member of the European Parliament's Advisory Committee on the Conduct of Members.