;First term Primeau was first elected to council in the 2005 municipal election. Mayor Gérald Tremblay's Montreal Island Citizens Union won a majority government in this election, and Primeau served as a member of the official opposition. In late 2006, he spoke against a proposal to rename Montreal's Parc Avenue after former Quebec premierRobert Bourassa. In the same period, he joined with fellow councillor Laurent Blanchard in a "bathrobe protest," showing up to a 6 am budget meeting dressed in his bathrobe and arguing that the meeting had been scheduled too early for public participation. In 2008, he was appointed to the municipal committee on transportation, infrastructure management, and the environment. Primeau was chosen as Vision Montreal's caucus leader in December 2008. Two months later, he publicly defended party leaderBenoît Labonté against criticisms from former executive directorRobert Laramée, who had called on Labonté to resign or be ousted in the face of weak polling numbers. Labonté ultimately resigned as Vision Montreal leader in June 2009 and was replaced by Louise Harel. After resigning as party leader, Labonté initially continued to serve as leader of the opposition on council. He stood down from the latter position in October 2009, following rumours of involvement in a municipal corruption scandal. According to a report in the Montreal Gazette, Primeau succeeded to the position of opposition leader and served for a brief term in late 2009 before resigning in favour of Louise Harel. ;Second term Primeau was re-elected to a second council term in the 2009 municipal election. Tremblay's party, now renamed as Union Montreal, was re-elected with another majority, and Primeau continued to serve in opposition. He was appointed to the city's finance committee in December 2009 and has also served as his party's sports and recreation critic. He stood down as caucus chair in 2012. Tremblay resigned as mayor against the backup of a serious corruption scandal in late 2012 and was replaced by Michael Applebaum. In early 2013, Primeau was appointed to a committee empowered to examine municipal contracts. By virtue of holding his seat on city council, Primeau is also a member of the Mercier–Hochelaga-Maisonneuve borough council.