After being defeated as a PQ candidate in La Peltrie in the 1985 general election and in a by-election in 1988, she was elected as the member of the Quebec National Assembly for Taillon in the 1989 general election. With the return of the PQ to government in 1994, premiers Parizeau, Bouchard and Landry appointed Marois to senior positions in the Quebec cabinet. She was instrumental in crafting policies to end confessional school boards in the public education system, she restructured the tuition system in post-secondary education, implemented a subsidized daycare program, instituted pharmacare and parental-leave plans and slashed the Quebec deficit under Premier Bouchard's "deficit zero" agenda. In 2001, Premier Landry appointed her Deputy Premier of Quebec, becoming the third woman after Lise Bacon and Monique Gagnon-Tremblay to assume the second-highest role in the provincial government.