This work explains the development of the direct applicability of fundamental rights in labor matters in some Latin American countries, where courts and legal doctrine postulate the validity of these rights as limits to the power of the employer. This applicability, commonly known as “horizontal effect” of fundamental rights between private individuals, is especially important in the field of labor law, as opposed to other areas of private law. Firstly, because contrary to what has been postulated by the constitutional narrative, this applicability originated within labor law at the beginning of the twentieth century, and secondly, because, with regard to labor law, this applicability does not increases judicial discretion, but, on the contrary, endeavors to limit corporate discretion. Consequently, by recognizing the particularisms of labor law, we will postulate that we are dealing with a diagonal, rather than a horizontal, effect of fundamental rights.


Fundamental Rights Horizontal effect Validity Labor Discretion