The appeal concerned diplomatic immunity, in particular diplomatic immunity in respect of claims brought by domestic servants against diplomats. When delivering a summary of the decision, Lord Sumption emphasised that exploitative employment practices under cover of diplomatic status is a recurring problem in the UK and elsewhere. Diplomats enjoy immunities under domestic and international law which limit their employees' access to the domestic courts.

Ms Reyes was a Pilipino national. She received a tier 5 visa to the UK facilitated by her employers, Mr and Mrs Al-Malki. Mr Al-Malki was a Saudi Arabian diplomat working in the embassy in London. The couple employed Ms Reyes in their private residence, promising her an 'honest' wage and suitable living arrangements. Her role entailed cleaning, helping in the kitchen and childminding. However, Ms Reyes alleged she was subjected to flagrant ill-treatment and was a victim of human trafficking throughout the course of her employment. She claims she worked excessive hours, was not afforded adequate accommodation, her passport was confiscated and that she was prohibited from leaving the house or communicating with others. She was not paid any salary until after her dismissal. Ms Reyes brought a claim against Mr and Mrs Al-Malki in the employment tribunal for race discrimination, unlawful deduction of wages and a failure to pay the National Minimum Wage.

The Court of Appeal held that the Employment Tribunal lacked jurisdiction because Mr Al-Malki was entitled to diplomatic immunity under Article 31 of the Vienna Convention. Ms Reyes appealed to the Supreme Court and Mr and Mrs Al-Malki cross-appealed, contending that they were never validly served with the claim form. This argument was subsequently rejected by the Supreme Court.

Articles 22 and 29 to 40 of the Vienna Convention on Diplomatic Relations deals with diplomatic immunity. These provisions confer different degrees of immunity on persons connected with a diplomatic mission, according to their status and function. Mr Al-Malki relied on Article 31 and Article 37 of the Convention claiming immunity from all civil proceedings.

The Supreme Court rejected this argument stating Article 31 confers immunity on diplomats regarding acts performed in the course of diplomatic duty. Diplomats who are no longer in the post and have left the country are afforded a more limited immunity under Article 39 (2), known as ‘residual immunity’.

The Court allowed the appeal of Ms Reyes concluding her maltreatment was not an act performed in the course of Mr Al-Malki's diplomatic functions and that this was a “personal transaction of their own.” It was held unanimously that when Mr Al-Malki’s employment concluded and the couple left the country, any diplomatic immunity once enjoyed came to an end. Owing to the decision arrived at on the immunity claim, it was unnecessary for the Court to address Ms Reyes' alternative argument based on the European Convention on Human Rights.
https://www.supremecourt.uk/cases/docs/uksc-2016-0023-judgment.pdf

Watch a summary of the decision delivered by Lord Sumption:
https://www.supremecourt.uk/watch/uksc-2016-0023/judgment.html