TREATY-BASED INVESTMENT ARBITRATION AND THE MFN CLAUSE: THE POSSIBLE COMMON DENOMINATOR BETWEEN JURISDICTION AND ADMISSIBILITY

This essay considers, in the framework of treaty-based investment arbitration, the use of the most-favoured-nation (MFN) clause in order to assert the jurisdiction of an international tribunal. It points out the two approaches that have emerged from arbitral decisions delivered in the last decade up until the most recent cases of Impregilo and Hochtief. According to the first approach, one of “extensive interpretation”, international investment law is to be comprehensively considered under both its substantive and procedural aspects. In this perspective, MFN clauses may be interpreted as a means to ensure facilitated access to international arbitration. Conversely, according to the “consensual” approach, insofar as treaty clauses which concern the dispute settlement resolution by arbitration are the main expression of a State’s consent to international jurisdiction, they cannot be modified or derogated by MFN clauses. However, it will be demonstrated that arbitral decisions have not led to genuinely conflicting outcomes. Indeed, the common line of the arbitral practice favourable to the extensive interpretation of MFN clauses relies on the difference between jurisdiction and admissibility, as the Hochtief decision demonstrates. As far as issues of mere admissibility are concerned, the MFN clause may work as an instrument facilitating access to an arbitral tribunal, if all the jurisdictional requirements have been met.