In the 1970s, Vollmer was politically active in the Anti-Imperialist League (), close to the Maoist KPD/AO, but did not join the party. They were activists against the Vietnam War. She became a member of the Bundestag in 1983 on the ticket of the Green Party, although she was not a party member. In 1985, she joined the Greens. In 1984, she was elected to the party's board in parliament, as one of three women. In 1985, she initiated a dialogue of the state and prisoners of the Red Army Faction. Within the party, she called in "Grüner Aufbruch" for a bridge between the "Realos" and "Fundis", those adjusting to the realities of possible developments, and fundamental thinkers. Due to the party principle of rotation she had to give up the parliamentary seat in 1985, but was reelected in 1987 and again in 1994, 1998, and 2002.Bundestag Datenhandbuch
