Keul has been a member of the
Green Party since 2006. Keul first became a member of the German
Bundestag in the
2013 elections, representing the
Nienburg II – Schaumburg constituency. In parliament, she served on the Committee on Legal Affairs and the Committee on Defense from 2013 until 2021. During that time, she served as her parliamentary group's spokesperson on legal affairs. From 2014 until 2017, she was also part of the parliament's
Council of Elders, which – among other duties – determines daily legislative agenda items and assigns committee chairpersons based on party representation. Following the
2017 elections, she joined the Subcommittee on Disarmament, Arms Control and Non-Proliferation. In addition to her committee assignments, Keul was a member of the German-American Parliamentary Friendship Group. She was also a member of the German delegations to the
Parliamentary Assembly of the
Organization for Security and Co-operation in Europe from 2014 and to the
Franco-German Parliamentary Assembly from 2019. On 7 June 2011, Keul was among the guests invited to the
state dinner hosted by President
Barack Obama in honor of
Chancellor Angela Merkel at the
White House. In 2019, Keul co-founded a cross-party support group for the
Treaty on the Prohibition of Nuclear Weapons. In the negotiations to form a so-called
traffic light coalition of the
Social Democratic Party (SPD), the Green Party and the
Free Democratic Party (FDP) following the
2021 German elections, Keul was part of her party's delegation in the working group on children, youth and families, co-chaired by
Serpil Midyatli,
Katrin Göring-Eckardt and
Stephan Thomae. In October 2024, Keul announced that she would not stand in the
2025 federal elections but instead resign from active politics by the end of the parliamentary term. ==Other activities==