A Liberal, he was re-elected in every election in one or another riding until dying in office in 1905. From 1902 to 1905, he was the Minister of Marine and Fisheries. When Joseph-Israel Tarte resigned from the Cabinet as Minister of Public Works in October 1902, Wilfrid Laurier, under pressure from Montréalers, gave Préfontaine the portfolio of Marine and Fisheries and, for the same reason, transferred to it from public works as "the major services relating to navigation."
A Liberal, he was re-elected in every election in one or another riding until dying in office in 1905. From 1902 to 1905, he served as the Minister of Marine and Fisheries. When Joseph-Israel Tarte resigned from the Cabinet as Minister of Public Works in October 1902, Wilfrid Laurier, under pressure from Montréalers, gave Préfontaine the portfolio of Marine and Fisheries and, for the same reason, transferred to it from public works as "the major services relating to navigation."