[3] In 1790 the young Gillet was sent by the electors of Rochefort to the assembly of Pontivy and in May of the same year he was elected to a position in the administration of the newly created département of Morbihan.
On 20 June the Vendean commanders, including Cathelineau offered to allow the Republican forces to withdraw with honour if they sent over the Convention deputies as hostages.
Gillet and Merlin de Douai attempted to flee, but the citizens cut the reins of their carriages, forcing them to stay.
After the siege was lifted, Gillet dismissed General Beysser, attacked Baco, the mayor of Nantes, and demanded the recall of Jean-Baptiste Carrier.
He fell ill, exhausted after two years of work to support the Republic, and died on 13 Brumaire (4 November 1795) at the age of 33.