Sources of Inherent Powers in International Adjudication

This chapter contributes to the debate about the sources of inherent powers in international adjudication. First, it contemplates the broader issue of whether the use of these powers amounts to exercising, or exceeding, an adjudicative body’s proper function. We argue the distinguishing feature of inherent powers is that they are “necessary” or “essential” judicial powers. There are also potentially basic limitations found in international law that restrict the disputing parties’ ability to take way certain inherent powers from an adjudicative body. Second, this chapter emphasizes the key role that constitutive instruments play in shaping the inherent powers of international courts and tribunals, which should alleviate the concerns about the legitimacy of these powers. Commentators typically favour one of the approaches to the sources of inherent powers in international adjudication, relying either on general principles, on the status or function of international courts, or on implied powers. We contend that these approaches do not conflict. Inherent powers can be derived from multiple sources: they can be express, they can be discretionary, they can be implied from the judicial function, or they can be rule-based with a grounding in general principles. Inherent powers are thus partly overlapping and all four sources can and do co-exist.