Mauritius v United Kingdom was an arbitration case concerning the status of the Chagos Archipelago and the attempts of the United Kingdom government to create a Marine Protected Area in British Indian Ocean Territory.
The Permanent Court of Arbitration was asked on 31 March 2011 to function as registry in the proceedings.
[3] In 2011, the government of Mauritius challenged Sir Christopher Greenwood's role in the arbitration proceedings on the grounds that his role as a UK Foreign and Commonwealth legal adviser could bias him in favour of the United Kingdom's claims to the Chagos Islands.
However, this was rejected by the tribunal on the basis that this "neither constituted nor continued an already existing relationship.
[5][6] On the 18 March 2015, the arbitral tribunal ruled that the Chagos Marine Protected Area was "not in accordance with the provisions of the Convention" and declared unanimously that in establishing the MPA surrounding the Chagos Archipelago the United Kingdom had breached its obligations under Articles 2(3), 56(2), and 194(4) of the Convention.