R v Secretary of State for Foreign and Commonwealth Affairs, ex parte Bancoult (No 2) [2008] UKHL 61 is a UK constitutional law case in the House of Lords concerning the removal of the Chagos Islanders and the exercise of the Royal Prerogative.

The Chagos Islands, acquired by the United Kingdom in 1814, were reorganised as the British Indian Ocean Territory (BIOT) in 1965 for the purpose of removing its inhabitants.

In 2000, Olivier Bancoult brought a judicial review claim against the Secretary of State for Foreign and Commonwealth Affairs for the initial ordinance which led to the Chagossian removal.

In response, Robin Cook, the Foreign Secretary, repealed the 1971 ordinance and announced he would not appeal against the decision, allowing the Chagossians to return home.

The reaction to the decision was negative,[1] with academics accusing the majority Law Lords of failing to do their job as members of the judiciary to "rework things like neo-imperial texts and outdated legal attitudes to the prerogative in order to cure obvious injustices and to vindicate a modern conception of the rule of law";[1] at the same time, their approach to legitimate expectation was also questioned, with the case described as an "unfortunate regression" from Council of Civil Service Unions v Minister for the Civil Service, where judges were willing to debate legitimate expectation in a similarly politically sensitive situation.

The Supreme Court of the United Kingdom ruled against reviewing the case on 29 June 2016 (R (on the application of Bancoult (No 2)) v Secretary of State for Foreign and Commonwealth Affairs).

First occupied by lepers from Mauritius, France acquired the islands in the late 18th century, and slaves were brought in from Africa and India to maintain coconut plantations placed there.

Accordingly, the Commissioner issued the Immigration Ordinance 1971, an Order in Council under the Royal Prerogative which required anyone entering or remaining in BIOT to seek permission beforehand.

The case, R (Bancoult) v Secretary of State for Foreign and Commonwealth Affairs, went to the Divisional Court, where it was heard by judges Richard Gibbs and John Laws.

Laws J held that it was "elementary" that "a legislature created by a measure passed by a body which is legally prior to it must act within the confines of the power thereby conferred"; in this case that the Commissioner's jurisdiction was to legislate "for the peace, order and good government" of BIOT.

[19] It concluded that: anything other than short-term resettlement on a purely subsistence basis would be highly precarious and would involve expensive underwriting by the UK Government for an open-ended period – probably permanently.

That objection being removed, I see no reason why prerogative legislation should not be subject to review on ordinary principles of legality, rationality and procedural impropriety in the same way as any other executive action.

The wording was to be treated "as apt to confer plenary lawmaking authority" and reviewing the Order was a matter for the government and Parliament, not for the courts, since it was a political issue of national security and foreign relations.

The standard requirement for legitimate expectation, as decided in R v North and East Devon Health Authority, ex parte Coughlan, was that there must be a "clear and unambiguous" promise made that led to a reliance or a detriment; Robin Cook's statement after the first Bancoult case could not be described as a clear and unambiguous promise of resettlement, and the requirements of reliance and detriment were not met.

At the same time, Bancoult raised questions about the oversight of Orders in Council, given that it highlighted the courts are unwilling to review a piece of executive legislation where there are political elements in play.

[1] Thomas Poole considered that the Law Lords had failed in their duty as members of the judiciary: "where old principles no longer fit contemporary constitutional and moral standards, why should we follow them?

Surely the judicial task is to rework things like neo-imperial texts and outdated legal attitudes to the prerogative in order to cure obvious injustices and to vindicate a modern conception of the rule of law".

[2] T. T. Arvind went further, drawing parallels with the judicial response to the Zong Massacre to argue that the decision, despite its formalist rhetoric, was in reality a pragmatic one which abandoned centuries of settled constitutional jurisprudence in relation to the limited scope of the Royal Prerogative.