General principles of law as applied by international administrative tribunals

This thesis provides a comprehensive analysis of general principles of law as a formal source of international administrative law. It examines how International Administrative Tribunals (IATs) apply these unwritten norms to fill regulatory gaps, interpret obscure provisions, and review administrative discretion or general regulatory instruments governing international civil service. Moreover, utilizing the ongoing work of the International Law Commission (ILC) on general principles of law as a theoretical benchmark, the study evaluates episodes of convergence and divergence between sectorial IAT practice and general principles in public international law. The research demonstrates that while IATs broadly mirror the main tenets established in the Commission work, particularly regarding functions and the dual taxonomy of principles, their jurisprudence diverges from other findings, ultimately providing empirical clarity on highly contentious questions, such as the methodology for deriving principles and their relationship with other sources of international law. Ultimately, this research offers significant added value to broader international legal discourse concerning this legal source.