In the house, Gugy voted regularly against the ministry of Sir Louis-Hippolyte La Fontaine, and during the famous debate on the Rebellion Losses Bill, Gugy, with Sir Allan Napier MacNab, was the principal leader of the opposition. In , his speeches fuelled the tension that finally exploded with the Burning of the Parliament Buildings in Montreal and the subsequent riots. Gugy reacted with his customary spirit on the night of the burning, seizing several of the agitators to stop them from setting upon the Speaker, Augustin-Norbert Morin. The next day, , Gugy climbed a lamp-post on the Champ de Mars and for two hours harangued the crowd that had gathered to launch an attack on the homes Sir Francis Hincks, Benjamin Holmes and his old enemy Sir Louis-Hippolyte La Fontaine, trying in vain to persuade them to disperse.