In the early 1970s, Jambrek was close to the reformist wing of the Slovenian Communist Party, led by
Stane Kavčič and
Ernest Petrič. After the authoritarian turn in the
Yugoslav Communist Party in 1972-73, which also affected Slovenia, Jambrek withdrew to purely academic work. He obtained professorship at the Faculty of Law and at the Faculty of Social Sciences of the University of Ljubljana. He studied
conflict theory and published a sociological study on rituals and rebellions. Between 1973 and 1975, he taught at the
University of Zambia in
Lusaka. In 1975, he published a comparative study on the transformation of tribal societies into nation states. Between 1975 and 1982, he published several books analyzing the structure of political decisions in Yugoslav local government. In the 1980s, Jambrek started collaborating with dissident intellectuals around the journal
Nova revija. He rose to prominence in 1987, when he published a thorough legal study on the possibilities of
Slovenian secession from
Yugoslavia in the collective volume
Contributions for a Slovenian National Program. In 1989, he left the Communist Party and became a founding member of the
Slovenian Democratic Union, one of the first democratic non-Communist parties organized during the
Slovenian Spring, 1988-1990. After the victory of the anti-Communist
DEMOS coalition in the first Slovenian free elections in spring 1990, he was appointed member of the
Slovenian Constitutional Court. In the years 1990-1991, he became one of the foremost members of the Constitutional Committee that wrote the new Slovenian Constitution. In 1993, he was appointed a member of the
European Court for Human Rights in
Strasbourg. Between June and November 2000, he served as Minister of the Interior in the short-lived centre right government of
Andrej Bajuk. In 2004, he was among the co-founders of the
liberal conservative platform
Rally for the Republic, and served as its chairman until 2008. Peter Jambrek was the editor at the European Public Hearing on
"Crimes Committed by Totalitarian Regimes" organised by Slovenian Presidency of the Council of the
European Union (January–June 2008) and the
European Commission. Despite never being its member, he was supportive of the
Slovenian Democratic Party until October 2011, when he voiced his sympathy for the newly established liberal centrist
Gregor Virant's Civic List. At the presidential election in 2022 he voiced his support to Lacanian psychoanalyst and philosopher
Nina Krajnik. Krajnik stated that Jambrek opened her eyes to presidential candidacy. ==End of political participation==