This paper approaches the problem of the labor-law-institutions legal applicability in work relationships of statutory nature, precisely from the perspective of the constitutional Rule of Lenity in labor law and the pro homine principle derived from the human rights protection systems and the international labor law norms system. The analysis is performed by taking into consideration two court decisions, one from the Consejo de Estado and the other one form the Corte Constitucional de Colombia. In these decisions, labor causes containing  a labor-stability plead of provisionally named individuals in the public function will be judged, allowing to determine that the mentioned rule and principle are no being taken into consideration when solving this type of causes by the administrative justice.