Duyvendak is the eldest son of a minister from Zeist. After his high school he studied sociology at the University of Amsterdam between 1976 and 1980. He did not finish his studies and instead became involved the leftwing Amsterdam action world: he became involved in the squatting movement and the anti-militarist action group Onkruit. In 1984 he was jailed for six weeks for having broken into the Dubbeldam military complex together with other members of Onkruit. Between 1984 and 1987 he wrote for the radical magazine Bluf!. After that he became involved in the Anti-Apartheid Committee "Get Shell out of South Africa" and he was an editor at the publisher Ravijn. De Telegraaf and HP/De Tijd-journalist Peter Siebelt have claimed that Duyvendak was involved with the violent Revolutionary Anti-Racist Action group. Duyvendak has always denied any involvement in violent action. In 1993 he began to work for MilieuDefensie and led their campaigns against the extension of Schiphol Airport. In 1999 he became the director of MilieuDefensie's bureau, which he remained until 2002.
Duyvendak was elected in the 2002 elections as a member of the GreenLeft list. In parliament he focused on environmental issues, spatial planning and transport. He was considered one of the most important 'green faces' of the GreenLeft. He has initiated some plans for governmental reform, including the temporary law on the referendum, together with Niesco Dubbelboer of the social-democrat PvdA, which was rejected in 2005. He also supported a constitutional amendment providing for referendums together with Dubbelboer and Boris van der Ham of the social-liberal D66 party. He has also researched the power of those committees, commissions and councils which were not, in his view, under sufficient parliamentary scrutiny. He also chaired the GreenLeft's campaign committee.
In 2008, Duyvendak published his book Klimaatactivist in de politiek. In this book, he described his run-ins with the law, including his 1984 jailing. He also mentioned how, in 1985, he admitted having stolen documents on nuclear power plants during a burglary on the Dutch ministry of economic affairs. Previously, Duyvendak always denied such involvement. The fall-out was severe, prompting calls for his resignation, especially after media reported that the burglary had led to threats of violence against civil servants.
Duyvendak subsequently announced his resignation from the Tweede Kamer on August 14, 2008. His resignation became effective on September 2, 2008. His seat was taken up by the next eligible GreenLeft candidate on the list of candidates, Jolande Sap.
<ref>tags exist, but no
<references/>tag was found