Legal aspects of granting British citizenship to Hong Kong citizens: from freedom of sovereignty to unilateral ban

On the execution of the Sino-British Joint Declaration in 1985, which had detailed resuming the exercise of China's sovereignty over Hong Kong, there was also an exchange of memoranda between the two sides. The British Memorandum to China stated the United Kingdom's pledge not to confer the right of abode in the United Kingdom on Holders of the British National (Overseas) passports who are Chinese inhabitants of Hong Kong. Following occurrence of a political turbulence in Hong Kong during 2019 and 2020, which led to a strained relations between Britain and China, British government unveiled plans to offer Hong Kong residents the chance to settle in the UK and ultimately apply for citizenship. The new immigration arrangements sparked furious reaction by China. There are doubts about the binding effect of the commitments embedded in the above-mentioned Memorandums, for a number of reasons. Scrutinizing the characteristics of a binding legal obligation in international law, this essay comes to the conclusion that the UK's pledge is a legally binding and unilateral one. Then it argues that revoking unilateral acts, which has been termed an “inherent right” by the ICJ, exceptionally could not be applied on the British Memorandum in this case.