Tétrault sought election to the National Assembly of Quebec in the 1994 Quebec provincial election as a Parti Québécois candidate in the extremely safe Liberal seat of Robert-Baldwin in west-end Montreal. The youngest candidate in the province at nineteen years of age, he was a CEGEP student during the election. Although it was generally recognized that he had no chance of winning, Tétrault's campaign received a fair amount of media attention. Profiled by the Montreal Gazette in August 1994, he described himself as "the kind of nationalist who is open to discussion." He finished a distant second against Liberal Pierre Marsan on election day. Tétrault later ran as a Bloc Québécois candidate in the Montreal-area riding of Brossard—La Prairie in the 2000 Canadian federal election. He was twenty-five years old during the campaign and operated his own marketing company. In an interview with the Gazette, he said that Canada should adopt a new model of politics and economics based on that of the European Community. He finished second against Liberal Party of Canada incumbent Jacques Saada. In 2002, Tétrault described the older wing of the Parti Québécois as having lost touch with modern Quebec. Two years later, he said that many people of his generation favoured "sovereignty if necessary but not necessarily sovereignty."
City councillor
Tétrault was elected to the Montreal city council in the 2001 municipal election as a Vision Montreal candidate in the Plateau-Mont-Royal division. During the campaign, he called for a speed limit reduction in the Plateau, increased security in parks and at metro stations, more co-op housing and support for local artists, and more parking spots for businesses. Vision Montreal lost the election to Gérald Tremblay's Montreal Island Citizens Union, and Tétrault served as a member of the official opposition. By virtue of his city council position, he also served on the Plateau-Mont-Royal borough council. When Pierre Bourque resigned as Vision Montreal leader to run for the National Assembly of Quebec in 2003, Tétrault said that he respected Bourque's decision but did not personally support it. He added that he would "have to look at the options" as to whether he would remain with the party. During the 2003 provincial election, Tétrault criticized the Quebec Liberal Party for its pledge to permit referendums on municipal demergers. He argued that the pledge would create instability for municipal government on the Island of Montreal, where several municipalities had recently been merged to create a united city. Later in the same year, he supported Mayor Tremblay's compromise plan to devolve some powers to the city's borough councils. Tétrault resigned from Vision Montreal to sit as an independent on March 4, 2004, and joined MICU on October 26 of the same year. In the 2005 municipal election, he ran for re-election in the Louis-Riel division of the Mercier–Hochelaga-Maisonneuve borough and was narrowly defeated by Vision Montreal incumbent Richer Dompierre. Early reports suggested that Tétrault had won by twelve votes, but a more thorough scrutiny confirmed Dompierre as the winner.
Private career
Tétrault has a Master of Arts degree in Political Science from the Université de Montréal. After leaving city council, he co-founded Groupe T & T Media with Paul Tietolman. In 2011, Mr. Rajiv Pancholy, former CEO of Microcell Connexions, joined the group of Tietolman Tetrault as a partner and shareholder and formed 7954689 Canada Inc. better known as Tietolman Tetrault Pancholy Media. In 2013, the group was granted three licenses to launch new AM radio stations in the Montreal market: English and French talk radio stations and a French sports radio station. As of August 2016, however, all three stations remain unlaunched, the French sports radio license has expired, and both of the other two licenses are also set to expire in November if they have not launched by then.