In an important decision with potentially far-reaching implications, the Supreme Court in Basfar v Wong [2022] UKSC 20 held that a diplomat may not assert immunity from civil proceedings concerning claims amounting to modern slavery.

The appellant, Ms Wong, a national of the Philippines, claimed to have been a victim of human trafficking as she was forced to work for the respondent, Mr. Basfar, a diplomat representing the Kingdom of Saudi Arabia in the UK, and his household in circumstances amounting to modern slavery after they brought her to the UK. Ms Wong brought a claim for unpaid wages and breaches of her employment rights before the Employment Tribunal. Mr. Basfar applied to have the proceedings struck out on the basis of diplomatic immunity. Under Article 31 of the Vienna Convention on Diplomatic Relations 1961 (“VCDR”), implemented in domestic law by the Diplomatic Privileges Act 1964, diplomatic agents enjoy complete immunity from the criminal jurisdiction of the receiving state and are also generally immune from its civil jurisdiction. However, there is an exception under Article 31(1)(c) of the Convention for civil claims relating to “any professional or commercial activity exercised by the diplomatic agent in the receiving State outside his official functions”. The Employment Tribunal found that Ms Wong's claim fell within this “commercial activity” exception, and so declined to strike out the claim, while the Employment Appeal Tribunal (“EAT”) held that Mr. Basfar was immune from suit. The EAT considered that the case raised a point of law of general public importance, and so it issued a certificate allowing the case to be appealed directly to the Supreme Court, “leapfrogging” the Court of Appeal.

The central question for the Supreme Court was whether the exploitation of Ms Wong in the manner alleged fell within the scope of the “commercial activity” exception, on the basis that the alleged conduct was outside the diplomat's official functions (at [27]). This question had previously been considered by the court in Reyes v Al-Malki [2017] UKSC 61, [2019] A.C. 735 – a case which involved a largely similar set of facts, but for one essential difference: in the present case Mr. Basfar remained in post, whereas in Reyes Mr. Al-Malki's diplomatic posting had ended during the course of the litigation. In Reyes, the court held that the respondent would not be entitled to diplomatic immunity, but doubts were expressed by members of the court as to whether Mr. Al-Malki would have been immune if he had remained in post. Precisely that situation arose for decision in Basfar v Wong.

The majority (Lords Briggs and Leggatt, with whom Lord Stephens agreed) applied the general rule of treaty interpretation set out in Article 31 of the Vienna Convention on the Law of Treaties 1969 in order to interpret the provisions of the VCDR as enacted into UK law by the 1964 Act. By so doing, their Lordships accepted from the outset that, as a matter of ordinary language, hiring a domestic worker is capable of being described as a commercial activity. However, in order to determine the scope of the exception, Lords Briggs and Leggatt considered it necessary to look, in addition to the ordinary meaning of the words, at the purpose of the relevant provision. It would be contrary to the purpose of conferring immunity on diplomatic agents to interpret the words “any… commercial activity” as including activities incidental to the ordinary conduct of diplomats’ daily lives in the receiving state, such as purchasing goods and services for personal use.

However, they determined that the same is not true when a domestic worker is exploited and compelled to work in circumstances of modern slavery. In rejecting Mr. Basfar's argument, the majority found that this activity is not comparable to an ordinary employment relationship that is incidental to the daily life of a diplomat. Rather, “[t]here is a material and qualitative difference between these two activities”: whereas employment is a voluntary relationship, entered into freely and governed by the terms of a contract, the essence of modern slavery is that the work is extracted by coercing and controlling the victim (at [43]). In justifying the distinction drawn, the majority cited two factors: first, the high degree of control exercised by Mr. Basfar over Ms Wong and her labour “was so extensive and despotic” as to place her in a position of domestic servitude; second, on the assumed facts, Mr. Basfar and his family had gained a substantial personal benefit by deliberately and systematically exploiting Ms Wong's labour for almost two years, initially for a fraction of her contractual entitlement, then latterly for no pay at all (at [52]). As the majority recalled, Article 42 of the Convention states that a diplomatic agent “shall not in the receiving state practise for personal profit any professional or commercial activity”. In the view of the majority, the exploitation of Ms Wong was “a deliberate and continuing course of conduct” (at [52]) and a “systematic activity carried on over a significant period” (at [56]), so “[it] would be not merely wrong but offensive to suggest that conduct of the kind disclosed by the assumed facts of the case is incidental to daily life, let alone the daily life of an accredited diplomat” (at [57]). Their Lordships held that this exploitation “is an abuse of the diplomat's presence in the receiving state and falls far outside the sphere of ordinary contracts incidental to the daily life of the diplomat and family members which the immunity serves to protect” (at [57]).

While it was not necessary to determine which form of modern slavery might best describe Mr. Basfar's conduct, the majority remarked that the assumed facts represented “a paradigm example of domestic servitude” (at [100]). On these assumed facts, the majority concluded that the claim brought by Ms Wong falls within the exception from immunity provided in Article 31(1)(c) of the Convention. As a result, if those facts are subsequently proved, Mr. Basfar does not have immunity from the civil jurisdiction of the UK courts (at [107]).

The minority (Lord Hamblen, Lady Rose) shared the majority's view that the normal employment of a domestic worker does not amount to “commercial activity” within the meaning of the Article 31(1)(c) exception to immunity (at [111]). However, they disagreed with the majority's conclusion that the conditions under which a person is employed or the manner in which they came to be employed can suffice to convert employment which would otherwise fall outside Article 31(1)(c) into a “commercial activity” within the meaning of the exception. Furthermore, they considered that developments, such as the conclusion of international instruments seeking to eliminate the practices of modern slavery, have not produced any effect on the meaning of the term “commercial activity”. Neither treaty practice, nor the jurisprudence of other states’ domestic courts (including a series of recent decisions by the US courts) provide any basis for suggesting that the meaning of “commercial activity” has been enlarged so as to now include trafficked employment (at [113]). According to the minority, such an expansion poses a risk to the scope of the important institution of diplomatic immunity, as it creates uncertainty as to which activities are subject to the exception. Furthermore, an expansive interpretation of the exception would be a cause for concern, as the minority foresaw the possibility of a number of difficulties arising: that there would be uncertainty as to breadth of the exception, given the difficulty in defining what amounts to trafficking and exploitation; that a domestic tribunal would be required to conduct intrusive and sensitive enquiries into diplomats' activities in order to determine whether immunity applied or not; and finally, that the UK's diplomats overseas would be exposed to the risk of retaliation, given that the legal framework of the VCDR operates on the basis of the principle of reciprocity (at [155]–[169]).

The majority addressed each of these concerns. While their Lordships acknowledged that it is not always clear where the boundary of exploitative employment within the exception to diplomatic immunity will lie, they dismissed the concerns about sensitive enquiries and possible retaliation: the parties to the VCDR must have considered and accepted the possibility of such enquiries when they established the “commercial activity” exception (at [102]), and there is no evidence to support the existence of a risk of retaliation which might impede the conduct of British diplomacy (at [105]–[106]).

The Supreme Court's decision represents a notable departure from the interpretation of the “commercial activity” exception in Article 31(1)(c) of the VCDR which has been adopted by the courts in other jurisdictions, most notably the US, where the exception has not applied in claims involving domestic workers who had been subject to exploitation (see Tabion v Mufti, 73 F 3d 535 (4th Cir 1996)). By confirming that diplomats are not entitled to rely on their diplomatic immunity in response to alleged breaches of modern slavery laws, the Supreme Court has struck a new balance between two important, but divergent, aims: on one hand, the practical necessity to respect the principle of diplomatic immunity which is indispensable to the proper functioning of diplomatic missions and to the peaceful and efficient conduct of relations between states; on the other, the growing concern to limit the opportunity for diplomatic immunity to be abused so as to address the pattern of exploitation of migrant domestic workers by foreign diplomats which has been documented in recent times.