[1] On 27 September 1792, he was named a member of the Commission of Six, charged with reporting on the state of the city of Paris and of bringing forward means of maintaining a watch on secret agitators and punishing incitement to murder.

[5] On 17 February 1793 he spoke in defence of General Georges Félix de Wimpffen, who was accused by two Jewish citizens of the departement of Moselle of having communicated with the Austrian commander during the siege of Thionville in 1792.

[12] 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[1] 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.