Leslie Thomas QC told The Times that the British court was one of the “last vestiges of colonialism” and had been superseded by the likes of the Caribbean Court of Justice (CCJ).

The JCPC is the final court of appeal for 27 Commonwealth countries, UK overseas territories and Crown Dependencies, though it – like the monarchy – came under renewed scrutiny in many of these countries during the disastrous royal tour of the Caribbean.

Mr Thomas said: “Contrary to the widely held belief that the Privy Council is more independent than the Caribbean Court of Justice, recent cases debunk this myth and in fact establish that the CCJ has in recent years been a much better protector of fundamental human rights than the Privy Council.

“The time is right to get rid of the last vestiges of colonialism and for Caribbean countries and peoples to have renewed faith in the CCJ. It has certainly proven its worth.”

However, Lord Sumption, a former judge of the UK Supreme Court and a member of the Privy Council, said the British court had played an important role in preventing executions in Caribbean countries.

There have been no executions in Caribbean countries since 2009, partly because of a JCPC ruling that they cannot be carried out on prisoners sentenced to death five or more years ago.

He also said the JCPC had the advantage of being the “top court of British common law in the world”, providing a level of consistency across jurisdictions.