OxHRH Research Associate and Andrew W Mellon Associate Professor of International Human Rights and Refugee Law, Dr Cathryn Costello along with Professor and Associate Dean (Research), Melbourne Law School, Michelle Foster have published ‘Non-refoulement as custom and jus cogens? Putting the prohibition to the test’ (2015) 46 Netherlands Yearbook of International Law in a special edition of the journal which focuses on jus cogens.

This research has been sponsored by the Allan Myers Oxford-Melbourne Programme.

Dr Costello and Professor Foster research notes that the norm of non-refoulement is at the heart of the international protection of refugees yet there remains a lack of consensus as to its status. In this contribution, we examine the question whether it has attained the status of a jus cogens norm. Adopting the methodology of ‘custom plus’ we first examine whether non-refoulement has attained the status of custom, concluding that widespread state practice and opinio jurisunderpin the view that it is clearly a norm of customary international law.  Moreover, much of this evidence also leads to the conclusion that it is ripe for recognition as a norm of jus cogens, due to its universal, non-derogatory character. In other words, it is a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted. The chapter then examines the consequences for its recognition as jus cogens, exploring some of the many ways in which jus cogens status may have meaningful implications for the norm of non-refoulement.