International Court of Justice (ICJ) is the principal judicial organ of the United Nations - UN Charter Chapter XIV. The court operates according to its Statute and Judges serve for 9 year terms. They may be re-elected by the United Nations.
Judge Christopher Greenwood was elected to the court in November 2008 and was willing to be re-elected. However, it became clear that he was not securing sufficient support within the UN General Assembly and his candidacy was withdrawn - The Guardian 20th November and BBC 21st November - How UK lost ICJ place to India
is that the Indian candidate - Dalveer Bhandari - is re-elected to the court. As The Guardian and other commentaries have noted, this is the first time that the court has not had a member from the United Kingdom.
Ronny Abraham of France, Abdulqawi Ahmed Yusuf of Somalia, Antonio Augusto Cancado Trindade of Brazil and Nawaf Salam of Lebanon have been
elected to the bench along with Judge Bhandari.
In July 2017 the UN General Assembly asked the ICJ to give an Advisory Opinion on the legal consequences of the separation of the Chagos Archipelago from Mauritius in 1965 - Press Release - Request for Advisory Opinion. This is a matter which has been the subject of extensive litigation in the UK - see, for example, R (Bancoult No.2) v Secretary of State for Foreign and Commonwealth Affairs  UKSC 35.