He was elected as a member of the New Democratic Party, but crossed over to the Bloc Québécois on February 28, 2013.
[1] He defeated incumbent MP Jean-Pierre Blackburn of the Conservative Party, who was Veterans Affairs Minister.
Patry was president of the Syndicat national des employés de l'aluminium d'Arvida, the union representing Rio Tinto Alcan workers in the riding.
Following his defection to the Bloc in 2013, Patry stated that "he voted for sovereignty in the 1980 and 1995 referendums and that he still hopes Quebec will one day become a country".
[3] He was rumoured to have considered resigning from the Bloc following the election of Mario Beaulieu as leader but remained with the party following the resignations of André Bellavance and Jean-François Fortin and was, with Louis Plamondon, one of two Bloc MPs until the House of Commons dissolved for the 2015 election.