[1] A supporter of Quebec sovereignty, he became active in the Parti Québécois and held press attaché positions for various members of René Lévesque's government.
When the PQ chose to de-emphasize its focus on Quebec sovereignty in the mid-1980s, he joined and served on the advisory board of the more hardline Rassemblement démocratique pour l'indépendance.
[2] After the Quebec Liberal Party was returned to power in the 1985 provincial election, Duthel became the public relations director for the Union des producteurs agricoles (UPA).
[3] In 1988, he organized an international conference against acid rain and fought to prevent Quebec's Steinberg supermarket chain from being sold to an Ontario consortium.
[4] In the same period, he supported a shift away from food aid policies, which he described as colonialist, in favour of promoting domestic agriculture in under-developed countries.
[6] In the 1988 Canadian federal election, he organized a party leaders debate on agriculture and free trade that Mulroney declined to attend.
[10] He promoted public transit over car use and, during labour difficulties in the winter of 1991-92, accused the corporation's maintenance workers union of inappropriate pressure tactics.
[11] In October 1992, he was hired as Vice-President, Public Affairs and Communications of Biochem Pharma Inc.[12] In this capacity, he announced the company's Montreal research tests with the anti-AIDS compound 3TC.
[13] He subsequently accused rival company Connaught of seeking to undercut its competition by dumping an American flu vaccine in Canada at a discounted price.
In 1998, Duthel became Vice President, Communications, Public and International Relations for Quebec's Société générale de financement (SGF).
Duthel attacked Michel Morin, a journalist at the French sector of Radio-Canada at the Conseil de Presse du Québec about a topo on TV about the story of large expenses.