By the plenitude of his power, the Pope can constitute a layman commissary Apostolic for ecclesiastical affairs, but according to the common canon law only prelates or clerics of the higher orders should receive such a commission (Lib. Sext., c. II, de rescr., 1, 3).
The Pope has the power to designate a lay commissary Apostolic for ecclesiastical affairs through his authority, yet according to common canon law, only bishops or high-ranking clerics should be appointed in such roles (Lib. Sext., c. II, de rescr., 1, 3).