In 1833, he was offered to join the Lê Văn Khôi revolt led by Lê Văn Khôi, son of the late governor of southern Vietnam Lê Văn Duyệt. He vowed to overthrow Emperor Minh Mạng and replace him with My Duong, the son of Minh Mạng's late elder brother Nguyễn Phúc Cảnh, who were both Catholics. Khoi appealed to other Catholics to join in overthrowing Minh Mạng and installing a Catholic emperor. They quickly seized the Citadel of Saigon in an uprising lasting two years. Marchand had declined the offer to joined.