In 1792 Bassenge returned to Liège with Charles François Dumouriez's French troops, which had captured the principality of Liège and the Austrian Netherlands from the Austrians, but the French defeat at the battle of Neerwinden forced him back into exile in France until 1795. Whilst in Paris from 1792 to 1795 he allied himself with the Girondins and was imprisoned and threatened with the guillotine during the Reign of Terror, until the Liége exiles intervened in his favour and won him Robespierre's support. On his release he returned to Liège on France's final annexation of it in 1795, becoming commissioner general to the executive directory within the departmental administration of Ourthe (one of the three departments created from Liège). In 1798 he was elected to represent that department in the Council of the Five Hundred in Paris (on which his younger brother also served - that brother later became sous-préfet for Montmédy and a member of the Corps législatif). Like many moderate republicans, he supported the 18 brumaire coup which brought Bonaparte and had no notion that Bonaparte would later make himself emperor. He gained a seat on the Corps législatif and defended his republican ideas in the "Décade philosophique", a scientific and literary journal headed by Pierre-Louis Ginguené and Amaury Duval.