The Supreme Court finds an administrative worker’s employment is not covered by State Immunity

Image of Sarah Fraser Butlin KC and Tamar Burton

The Supreme Court has today handed down judgment in Royal Embassy of Saudi Arabia (Cultural Bureau) v Costantine [2025] UKSC 9. Sarah Fraser Butlin KC and Tamar Burton acted for the successful Respondent, Antoinette Costantine. They were instructed by Zimmers.

From 2010 to 2018 Mrs Costantine was employed in Saudi Arabia’s Cultural Bureau in London as a post room clerk and then as a secretary to the Head of the Cultural Affairs Department. She presented a claim to the Employment Tribunal of discrimination and harassment because of her Christian Catholic religion. Saudi Arabia asserted that her claim was barred on the basis of state immunity. 

The Employment Tribunal’s decision

At a preliminary hearing in June 2021 Employment Judge Brown concluded that the Claimant’s employment was not an exercise of sovereign authority and therefore state immunity did not apply. Applying the Supreme Court’s decision in Benkharbouche v Embassy of the Republic of Sudan (Secretary of State for Foreign and Commonwealth Affairs and others intervening) [2017] UKSC 62; [2019] AC 777 (“Benkharbouche”), the Tribunal concluded that the Claimant’s employment fell within the middle category of administrative and technical staff and that her employment was not an exercise of sovereign authority. Therefore, it held that the Claimant’s European law claims could proceed to a final hearing. 

The Employment Appeal Tribunal

Saudi Arabia appealed to the Employment Appeal Tribunal. The claim was rejected on the sift by Mr Mathew Gullick KC, sitting as a Deputy Judge of the High Court.

At a rule 3(10) hearing, His Honour Judge Barklem also rejected the appeal. 

The Court of Appeal

Saudi Arabia appealed to Court of Appeal but shortly before the appeal hearing its lawyers came off the record after not being paid.

Saudi Arabia did not instruct a new legal team, attend the Court of Appeal or make an application for an adjournment, despite being advised to do so by the Court of Appeal on several occasions before the hearing.

On 13 March 2024 Lord Justice Underhill, sitting with Lord Justice Warby and Lord Justice Newey, dismissed the appeal, without determining its merits, due to Saudi Arabia’s non-attendance.

The Supreme Court

Saudi Arabia then appealed to the Supreme Court on three grounds. The appeal was heard on 6 November 2024.

On the first ground, the Supreme Court agreed with Saudi Arabia that section 1(2) of the State Immunity Act 1978 (“SIA”) required the Court of Appeal to consider whether state immunity applied notwithstanding the failure of Saudi Arabia to attend its own appeal. However, the Supreme Court dismissed Saudi Arabia’s appeal.

The Supreme Court concluded had the Court of Appeal considered the issue of state immunity rather than dismissing the appeal outright, it would have concluded that Saudi Arabia was not entitled to state immunity.

Lord Lloyd-Jones (with whom Lord Briggs, Lord Hamblen, Lord Leggatt and Lord Burnett all agreed) concluded that the Employment Judge had correctly applied the law on state immunity to the facts of Mrs Costantine’s employment.

In this judgment the Supreme Court has endorsed the approach in the 2017 Supreme Court decision of Benkharbouche as applying to administrative and technical workers.

In Benkharbouche the Court had considered the application of state immunity to domestic staff within a diplomatic mission. It held that the immunity conferred on a foreign state by section 4(2)(b) and section 16(1)(a) of the SIA 1978 exceeded in certain respects the immunity required by customary international law. In particular, it held that section 16(1), which extended state immunity to the claims of any employee of the diplomatic mission, irrespective of the sovereign character of the employment or the acts of the state complained of, could not be justified by reference to any rule of customary international law. This, it considered, led to an infringement of the right of access to a court under article 6 ECHR and the right to an effective remedy before a tribunal under article 47 of the EU Charter. As a result, it granted a declaration of incompatibility under the Human Rights Act 1998 (“the HRA”) and disapplied the two provisions for inconsistency with EU law in so far as they applied to any claims derived from EU law.

In response to that judgment, on 2 February 2023 the State Immunity Act 1978 (Remedial) Order (SI 2023/112) corrected the unlawful aspects of the SIA. The Remedial Order applies to proceedings in respect of causes of acting arising on or after 18 October 2017.

The Supreme Court has today concluded that Lord Sumption’s approach to state immunity at §54-55 Benkharbouche accurately reflects the position in customary international law and applies equally to administrative and technical workers.

In determining the question of immunity, the first issue is whether the state entered into the contract of employment in the exercise of sovereign authority. This will require an examination of the nature of the relationship between the parties to the contract of employment and the functions which the employee is employed to perform. At §70 Lord Lloyd-Jones stated that:

“While the role of technical and administrative staff is, by comparison with diplomatic agents, essentially ancillary and supportive, this is not determinative. It may be that the ancillary and supportive functions of some employees are sufficiently closely connected to the governmental functions of the mission to make their employment an exercise of sovereign authority.”

Second, even if the contract itself was not entered into in the exercise of sovereign authority, immunity may apply because the state engaged in the conduct complained of in the exercise of sovereign authority. Any claim for reinstatement is likely to be defeated by immunity on this basis.

Lord Lloyd-Jones rejected Saudi Arabia’s submission that Ms Costantine’s case engaged an investigation into sovereign decisions of the mission. At §76 the Court held:

“the appellant has produced no evidence to support the suggestion that the treatment of the respondent engaged the State’s sovereign interests. There has been no accusation of wrongdoing on the part of the respondent. There has been no disciplinary investigation against her. There has been no suggestion that her dismissal was connected in any way with sovereign matters such as State security. If the appellant were entitled to immunity in these circumstances, there would be such an entitlement in every case of dismissal of a member of the administrative staff of a mission.”

The Court has therefore confirmed that administrative and technical workers, such as Ms Constantine, fall within the ambit of Benkharbouche.

To read the full judgment, click here.