UCL Faculty of Laws


In-Person | Denouncing the ‘One Voice’ Doctrine

28 February 2024, 6:00 pm–7:00 pm

Dominos in a line behind the 1 brick

This lecture is part of the International Law Association (British Branch) Lecture Series

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UCL Laws

ILA lecture on 'Denouncing the 'One Voice' Doctrine'

Speaker: Mr. Marcus Teo (National University of Singapore)

Chair: Dr Ugljesa Grusic (UCL)

About the Lecture:

The ‘one voice’ doctrine holds that the executive’s recognition of foreign States and governments is conclusive evidence of their existence and status in English proceedings. However, this doctrine – properly understood as a deeming rule akin to an irrebuttable presumption of law – is riddled with theoretical and practical problems. In this lecture, I argue that the ‘one voice’ doctrine should be abandoned, in favour of an alternative (less radical) rebuttable presumption. Three arguments will be made. First, the doctrine is unjustifiable: it is motivated by over-broad accounts of the executive’s prerogative in foreign affairs and the judiciary’s ability to impliedly recognise foreign States and governments on the UK’s behalf. Second, it is uncertain: questions remain – on the doctrine’s application to de facto foreign governments, its relationship with foreign affairs non-justiciability, and the breadth of its exceptions – which its existing justifications, rooted in prerogative power, cannot answer. Third, the doctrine leads to unpalatable results: it undermines the purpose of other doctrines which operate contingently upon it, like state immunity, the foreign act of state doctrine, and the rule against the enforcement of foreign public laws.

About the Speaker:

Marcus Teo is a Sheridan Fellow at the National University of Singapore, where he focuses on public law, the conflict of laws, and foreign relations law. His research interests lie in the theoretical foundations of common law judicial review, as well as the doctrinal content of the relationship between international law and domestic law. Marcus’ work has been published in the Cambridge Law Journal, the International & Comparative Law Quarterly, the International Journal of Constitutional Law, and Public Law, among others. He is an Advocate and Solicitor of the Supreme Court of Singapore and holds degrees from NUS and the University of Cambridge.

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