In 1779 Johnstone was offered, and accepted, a post as commodore of the Lisbon Station , despite his previous attacks on the ministry, and his support for conciliation over military intervention. He justified himself with the argument that since France had entered the war on the American side, he could no longer support staying out of the war. He was promised an assignment on the Portuguese station, before which he cruised off the French coast in his flagship , looking for evidence of invasion preparations. It soon became known that the French and Spanish fleets intended to unite and form a large single fleet to invade England. Johnstone took "Romney" to join Admiral Sir Charles Hardy's Channel Fleet, and pressed him to seek battle. Hardy instead preferred to avoid action at first, wearing down the enemy fleet at sea while his own continued to refit and resupply from the naval bases along the English coast. Hardy's tactics were successful, and rather than confront a fresh and well-equipped British fleet, the enemy armada abandoned their plans and returned to French ports.