She was a member of the Danish parliament (Folketinget) from 21 September 1971 to 22 January 1995 and from 20 November 2001 until 8 February 2005. She was a minister of various cabinets under Anker Jørgensen, and Poul Nyrup Rasmussen. In 1971 she was elected to the Odense City Council where she served just one term and resigned in 1973. In 1971 and 1975-1978 she held the position as minister of education, where she changed the Primary School Act in 1975 with the support from the majority of the other parties. On 5 November 1975 Bjerregaard hired an external chancellor for Roskilde University. Venstre and Conservative People's Party wanted to abolish the university, but thanks to the independent politician, former Conservative People's Party member Hans Jørgen Lembourn, the university was saved. In 1976 she introduced restricted admission at the universities meanwhile secured the protection of minorities. In 1977 Bjerregaard got the law about Erhvervsfaglige Grunduddannelser - EFG (Vocational basic training) approved. With former head of department Erik Ib Schmidt she launched the ambitious, complete education plan U 90 from 1978.