He jumped to provincial politics in the 2003 provincial election and was elected in Frontenac. After being for nearly two years the Parliamentary Secretary for the Minister of Municipal Affairs, Sport and Leisure he would become after a Cabinet shuffle the Minister of Labour in 2005. When Yvon Vallières took time off for health reasons in 2006, he would temporarily had the portfolios of Agriculture, Fisheries and Food for a few weeks before obtaining them after the 2007 elections when Vaillières was no longer part of the cabinet. He was also temporarily the Minister responsible for Chaudière-Appalaches prior to the 2007 elections.
Lessard kept the same Cabinet positions following the Liberal majority gained in the 2008 elections. On June 23, 2009, following a Cabinet shuffle, Lessard replaced Nathalie Normandeau as the Minister of Municipal Affairs and Regions and Land Occupancy while Claude Béchard became the new Minister of Agriculture. [1][usurped]