R (on the application of Bancoult) (No 3) v Secretary of State for Foreign and Commonwealth Affairs [2018] UKSC 3

Chagossian representative Bancoult challenged the 2010 Marine Protected Area around the Chagos Islands, alleging improper motive to prevent resettlement and inadequate consultation regarding Mauritian fishing rights. The Supreme Court dismissed the appeal, holding the MPA was lawfully established by the Foreign Secretary.

Facts

The appellant, chair of the Chagos Refugees Group, challenged the establishment of a Marine Protected Area (MPA) around the British Indian Ocean Territory (BIOT) by Proclamation No 1 of 2010, which included a ‘no-take’ zone banning commercial fishing. The Chagossians had been removed from the islands in 1971-1973 and remain prohibited from returning under the 2004 BIOT Constitution and Immigration Orders.

The challenge had two limbs: (1) that the MPA decision had an improper ulterior motive, namely to make Chagossian resettlement impracticable; and (2) that the consultation preceding the decision was flawed by failure to disclose the arguable existence of Mauritian inshore fishing rights.

Central to the improper purpose argument was a purported US Embassy diplomatic cable dated 15 May 2009, published by Wikileaks and subsequently by The Guardian and The Telegraph, recording a meeting on 12 May 2009 between FCO officials (Mr Colin Roberts and Ms Joanne Yeadon) and US officials. The cable purportedly recorded Mr Roberts stating there would be ‘no human footprints’ or ‘Man Fridays’ on BIOT’s uninhabited islands and that establishing a marine park would ‘put paid to resettlement claims’.

Issues

Admissibility of the Cable

Whether the Wikileaks cable was admissible in evidence, given articles 24 and 27(2) of the Vienna Convention on Diplomatic Relations 1961 providing for inviolability of diplomatic archives and correspondence.

Improper Purpose

Whether the MPA decision was vitiated by an improper ulterior motive to prevent Chagossian resettlement, and whether exclusion of the cable before the Administrative Court materially affected the outcome.

Fishing Rights Consultation

Whether the consultation was flawed by failure to mention arguable Mauritian fishing rights.

Arguments

The appellant argued that the cable demonstrated an improper motive and that restriction on cross-examination deprived the appellant of the opportunity to properly test the FCO witnesses’ evidence. On fishing rights, the appellant contended there was credible evidence of a UK undertaking to Mauritius regarding fishing, which should have been disclosed in the consultation.

The respondent argued that use of the cable breached article 24 of the Vienna Convention (inviolability of diplomatic archives), and that in any event no improper purpose existed as the decision was personally made by the Foreign Secretary, Mr David Miliband, based on environmental and scientific merits.

Judgment

Admissibility of the Cable

The Supreme Court held the cable was admissible. Lord Mance concluded that inviolability under articles 24 and 27(2) in principle extends to preclude use of mission archive documents in domestic courts of the host state, rejecting Dr F A Mann’s narrower view. However, two qualifications apply: the document must remain part of the mission archive, and its contents must not have become so widely disseminated as to destroy confidentiality. Here, the cable likely emanated not from the London Embassy but from elsewhere in the US government, and in any event had entered the public domain through Wikileaks publication.

Lord Sumption, agreeing, emphasised that designation of a document as belonging to the mission’s archives depends on whether it remains under the control of the mission’s personnel. Once documents enter the public domain, the confidentiality protected by article 24 is destroyed.

Improper Purpose

The majority (Lord Mance, with Lord Neuberger, Lord Clarke and Lord Reed agreeing) held that even if the cable had been admitted, it could not realistically have altered the Administrative Court’s conclusion. The Court reviewed the evidence showing that the MPA proposal originated from independent environmental activity (the Pew Environmental Group), that Mr Miliband was the ultimate decision-maker acting against his officials’ recommendation for a slower approach, and that his decision was motivated by political and environmental considerations rather than any desire to frustrate resettlement.

The Court held that even assuming improper motivation on the part of Mr Roberts or Ms Yeadon, this could not be attributed to the Foreign Secretary. The Carltona principle had no application as the Secretary of State personally took the decision, not civil servants acting on his behalf. The Court observed that the creation of the MPA could not itself effectively prevent resettlement; what prevented return was the 2004 Order, not the MPA.

Dissent

Lord Kerr (with Lady Hale agreeing on this point) dissented, holding that exclusion of the cable had materially affected cross-examination and the court’s assessment of the evidence. The correct test was whether admission of the cable could have made a difference, not whether it would have done. There was a substantial possibility the Divisional Court might have reached different conclusions on credibility and on whether the Foreign Secretary’s decision was impeachable for being taken in ignorance of a concealed improper motive.

Fishing Rights

The Court unanimously granted permission to appeal but dismissed this ground. The absence of express reference to arguable Mauritian fishing rights in the consultation did not undermine its fairness. The potential impact on commercial fishing was obvious, Mauritius had opportunity to respond but did not engage (instead pursuing sovereignty claims), and others including Chagossians did raise fishing concerns. The Court noted that since the Court of Appeal’s judgment, an UNCLOS arbitration award of 18 March 2015 had found binding UK undertakings regarding Mauritian fishing rights in the territorial sea, but the significance of this was not before the Court.

Implications

Diplomatic Inviolability

The decision clarifies the scope of inviolability under articles 24 and 27(2) of the Vienna Convention. Inviolability in principle prevents the use of mission archive documents in domestic courts, but this protection is subject to two important qualifications: (1) the document must remain part of the mission’s archive (under control of the mission’s personnel), and (2) confidentiality may be lost where contents have entered the public domain. The decision confirms the continuing authority of Shearson Lehman Bros Inc v Maclaine Watson & Co and rejects the narrower interpretation urged by Dr F A Mann.

Judicial Review of Ministerial Decisions

The majority’s approach reinforces that where a minister personally takes a decision based on properly framed advice, improper motives held by subordinate civil servants will not vitiate the decision unless they influenced the ultimate decision-maker. The Carltona principle concerns delegation of ministerial powers and has no application where the minister personally decides.

Practical Significance

The decision confirms the lawfulness of the BIOT MPA, though the fishing rights dimension has subsequently been affected by the UNCLOS arbitration. The case remains significant for Chagossians’ ongoing campaign for resettlement, which continues through separate judicial review proceedings concerning the November 2016 decision to maintain the resettlement ban. The case is also significant as a leading modern authority on diplomatic inviolability in the age of Wikileaks and mass document disclosures.

Verdict: Appeal dismissed. The Supreme Court held the Wikileaks cable was admissible (dismissing the respondent’s cross-appeal), but (by majority, Lord Kerr and Lady Hale dissenting) its admission could not realistically have altered the outcome on the improper purpose challenge. Permission to appeal on fishing rights was granted but the appeal on that ground dismissed.

Source: R (on the application of Bancoult) (No 3) v Secretary of State for Foreign and Commonwealth Affairs (Respondent) [2018] UKSC 3