As the political situation in Lower Canada worsened by 1837, with Clément-Charles Sabrevois de Bleury and George Moffatt, Quesnel arranged a public meeting at Montreal in support of the government. Two months later, Lord Gosford appointed him to the Executive Council of Lower Canada. When the Lower Canada Rebellion broke out, Quesnel was condemned as a "vendu" by the Patriotes and his brother, Joseph-Timoléon, was forced to flee L’Acadie and give up his magistrate’s commission.