He fled, and on 28 July he was proclaimed a traitor. Together with other Girondin deputies, he took refuge in Caen, where they attempted to regroup under the leadership of Jérôme Pétion de Villeneuve. Together with Charles Jean Marie Barbaroux, Lesage served as secretary to this group. After Thermidor  After the 9 Thermidor, he was recalled to the Convention (19 Ventôse Year III), where he denounced both 'crazed royalism and the fury of terrorism'. In April 1795 he was appointed to the 'Commission of Seven', (subsequently expanded to eleven), charged by the Convention with devising means of bringing the Jacobin Constitution of 1793 into effect. Instead, the commission drafted the entirely new Constitution of the Year III, which was laid before the Convention in June, adopted in August and confirmed by referendum in September. He became a member of the Committee of Public Safety and took an interest in military affairs during the War in the Vendée, placing Lazare Hoche and Jean-Baptiste Annibal Aubert du Bayet at the head of the armies of the Republic in the region. In the Convention, Lesage also advocated bringing Charles-Gilbert Romme and his associates to justice before the criminal court of the Seine departement, and opposed proposals for a union of France and Belgium. On 15 October 1795 (23 Vendémiaire Year IV) he was elected to the Council of Five Hundred where he made his mark principally in defending General Francisco de Miranda, who was suspected of conspiring with royalists against the Directory, and of plotting a military coup. He died during a session of the Council.
He fled, and on 28 July he was proclaimed a traitor. Together with other Girondin deputies, he took refuge in Caen, where they attempted to regroup under the leadership of Jérôme Pétion de Villeneuve. Together with Charles Jean Marie Barbaroux, Lesage served as secretary to this group. After Thermidor 
After the 9 Thermidor, he was recalled to the Convention (19 Ventôse Year III), where he denounced both'crazed royalism and the fury of terrorism'. In April 1795 he was appointed to the'Commission of Seven', (subsequently expanded to eleven), charged by the Convention with devising means of bringing the Jacobin Constitution of 1793 into effect. Instead, the commission drafted the entirely new Constitution of the Year III, which was laid before the Convention in June, adopted in August and confirmed by referendum in September. He became a member of the Committee of Public Safety and took an interest in military affairs during the War in the Vendée, placing Lazare Hoche and Jean-Baptiste Annibal Aubert du Bayet at the head of the armies of the Republic in the region. In the Convention, Lesage also advocated bringing Charles-Gilbert Romme and his associates to justice before the criminal court of the Seine departement, and opposed proposals for a union of France and Belgium. On 15 October 1795 (23 Vendémiaire Year IV) he was elected to the Council of Five Hundred where he made his mark principally in defending General Francisco de Miranda, who was suspected of conspiring with royalists against the Directory, and of plotting a military coup. He died during a session of the Council.