No diplomatic immunity for perpetrators of modern slavery

United Kingdom

In a groundbreaking judgment, the UK Supreme Court has ruled, for the first time, that the alleged exploitation of a domestic worker falls within the commercial activity exception to a diplomat’s immunity under article 31(1)(c) of the Vienna Convention on Diplomatic Relations 1961. The relevant provisions of the Convention apply, and have the force of law, in the UK by virtue of section 2 of the Diplomatic Privileges Act 1964.

Factual background

Ms Wong, a migrant domestic worker, commenced an Employment Tribunal claim against her former employer, Mr Basfar, a diplomat resident in the UK. Ms Wong alleged that she was the victim of human trafficking and that Mr Basfar had – prior to her escape from his home - forced her to work for the Basfar family under abusive conditions. Ms Wong further alleged unpaid wages and breaches of her employment contract.

Noting that none of the allegations had been admitted by Mr Basfar, the court stated that it “must assume” those allegations to be true so as to test Mr Basfar’s argument that, even if the facts alleged were proven, the claim against him could not succeed because he had diplomatic immunity.

The procedural history

In response to Ms Wong’s Employment Tribunal claim, Mr Basfar asserted immunity and applied to have the claim struck out. The tribunal found in Ms Wong’s favour. However, Mr Basfar successfully appealed to the Employment Appeals Tribunal, and Ms Wong was permitted to appeal directly to the Supreme Court (leapfrogging the Court of Appeal).

The issues

In response to Mr Basfar’s immunity assertion, Ms Wong argued that (i) human trafficking is a commercial activity; (ii) the claim relates to human trafficking ; and (iii) consequently, her claim relates to a commercial activity allegedly exercised by Mr Basfar and so falls within the exception to immunity provided in article 31(1)(c) of the Convention.  

The Supreme Court had previously considered a similar issue in Al-Malki v Reyes [2017] UKSC 61, where the alleged facts bore a close resemblance to the present case. However, in Reyes, as the diplomat’s posting had ended during the litigation, it was not necessary for the Supreme Court to consider whether the diplomat benefited from immunity. This was because the court had concluded that, after a diplomat’s functions have ended, immunity for past acts continues to subsist only for acts which were performed in the exercise of those functions, which the alleged acts in Reyes were not.

Diplomatic immunity: The legal framework under international law and under English law

The principle of diplomatic immunity is fundamental to both international and national law. At the international level, the principle is contained in article 31 of the Convention, which provides that “A diplomatic agent shall enjoy immunity from the criminal jurisdiction of the receiving State. He shall also enjoy immunity from its civil and administrative jurisdiction,” with limited exceptions including a professional and commercial activity exception (article 31(1)(c)). As recorded in the recital to the Convention, diplomatic immunity is functional in nature, and it is provided “to ensure the efficient performance of the functions of diplomatic missions as representing States.”

Under English law, diplomatic immunity is conferred through the Diplomatic Privileges Act 1964, section 2(1).

The question for the Supreme Court was whether Mr Basfar’s alleged conduct fell under the “commercial activity” exception to diplomatic immunity. The Supreme Court was not required to determine the truth of the claims, and did not do so.

The Supreme Court’s judgment

In Wong v Basfar [2022] UKSC 20, all members of the Supreme Court agreed with Mr Basfar’s argument that the ordinary employment of a domestic worker by a diplomat does not itself constitute a “commercial activity” within the meaning of the exception.

The majority of the court looked beyond the ordinary meaning of the words and considered the context and purpose of the commercial activity exception. The court ruled that activities such as dry cleaning and domestic help were incidental to the ordinary daily life of diplomats, and so they fell within the rationale for diplomatic immunity.

However, Lord Leggatt, Lord Briggs and Lord Stephens rejected Mr Basfar’s argument that exploiting a domestic worker is comparable to an ordinary employment relationship of a kind that is incidental to the daily life of a diplomat. It was held that there is a material and qualitative difference between such exploitation and an ordinary employment relationship. Importantly, employment is a voluntary relationship, whereas the essence of modern slavery is that work is extracted by coercing and controlling a victim - which usually involves exploiting the vulnerable characteristics of the victim.

On the assumed facts, it was held that Mr Basfar and his family enjoyed Ms Wong’s services at a substantial financial benefit, and that benefit could be described as a commercial activity practised for personal benefit, contrary to article 42 of the Convention.

In the majority’s view, in order to interpret and apply article 31(1)(c) of the Convention, the crucial distinction is between:

  1. ordinary domestic employment arrangements that are incidental to the daily life of a diplomat in the receiving state and which are covered by immunity, and
  2. servitude, forced labour and human trafficking (recognised concepts in international law and known together under the description of modern slavery) which would come within the commercial activity exception to immunity.

Notably, this is where the minority disagreed with the majority of the court. The minority did not agree that the conditions under which a person is employed or how they came to be employed could transform an employment relationship - which is not a commercial activity - into an activity falling into that exception.


In summary, on the assumed facts, the majority of the court found that the claim fell within the commercial activity exception to immunity under the Convention, and the judgment of the Employment Tribunal was reinstated. Accordingly, if the facts contended by Ms Wong are proven, Mr Basfar will not be immune from the civil jurisdiction of the English courts. Unless admissions are made, the case will return to the Employment Tribunal to determine the truth of the allegations. 


The ruling has been described as a significant victory for migrant domestic workers employed by foreign diplomats. The majority of the Supreme Court were unequivocal in their comments that the exploitation by a diplomat of a migrant domestic worker, to provide labour in circumstances of modern slavery, would constitute an abuse of the diplomat’s presence in the receiving State. Similarly, the minority of the court were dismayed by the number of cases of domestic servitude in the UK, including within diplomats’ homes.

The judgment has the potential to have global repercussions. Firstly, the court’s judgment related to interpreting the Convention, and so it is likely that the judgment will be considered in similar cases heard by courts in other states which apply the Convention. Secondly, time will tell whether the concern expressed by the minority - that an expansive or unusual interpretation of the commercial activity exception may expose British diplomats to retaliatory measures abroad - will materialise. Whilst there were two interveners in this case (Kalayaan, which is a charity supporting domestic migrant workers, and the United Nations Special Rapporteur on Trafficking in Persons especially Women and Children), the Secretary of State for Foreign, Commonwealth and Development Affairs did not intervene, which may suggest the risk of such retaliatory action was not considered to be a real concern by the UK Government.

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