Abstract
The public order clause is an instrument of private international law that limits the possibility of applying the law of a designated country in cross-border contractual relations. The role of the clause is to protect the specific interests and values of a given legal order, the importance of which is so significant that it justifies refusing to apply foreign law or limiting the scope of its application. From the point of view of the subject of this study, the public order clause could potentially be applied by national supervisory authorities in a situation of a threat to the security and stability of a given financial market. Thus the purpose of this article, in which the author uses the functional approach of the comparative legal method, the historical-descriptive method and the dogmatic method, is to verify the thesis about the possible use of the public order clause as an instrument supporting the process of building sustainable finance, along with its limitations in the form of the French concept of effet atténué and also from a comparative and cross-border perspective.