Prince William and his wife Catherine, Duchess of Cambridge will visit the Bahamas, Jamaica and Belize next month

The visit will largely focus on environmental issues, with William and Catherine taking a trip to Coral Vita, a coral farm in the Bahamas focused on reef restoration which was one of the first winners of the prince's £1 million Earthshot Prize.

The timing of the visit to the island nations is seen as a bid to persuade them not to follow Barbados in stepping away from having Queen Elizabeth as head of state.

In December, Jamaica's Prime Minister, Andrew Holness, said there was "no question that Jamaica has to become a republic".

And last week, governor-general Sir Patrick Allen told how the newly-created post of Ministry of Legal and Constitutional Affairs had been tasked with reforming the country's laws and reviewing the constitution, including "the process to shift Jamaica's status as a constitutional monarchy".

Last year, Belize's Prime Minister John Briceno refused to rule out his nation following Barbados.

He said: "We need to find what fits Belize best."

Rumours of the visit surfaced in January when representatives for William, who once trained with the Welsh Guards in Belize, and his wife were seen on Belize's island Ambergris Caye in what was described as an "advance party" ahead of an official visit in the spring.

A source said: "Their people were very secretive and kept saying this had to be kept very quiet, but on a small island like Ambergris Caye it's impossible to keep anything quiet for very long.

"They were talking about a four-day visit to Belize in March as part of a longer trip to this part of the world. They said William and Kate might visit the Caye and also go to mainland Belize. It's all anyone here is talking about. We are so excited."

It is unclear if the couple's children, Prince George, eight, Princess Charlotte, six, and two-year-old Prince Louis, will join them on the visit.