Antigua and Barbuda has dropped its pledge of allegiance to the King – two months before he is due to visit the Caribbean country.
Charles will now use the trip at the end of October to urge the nation to stay in the Commonwealth, without having him as head of state.
The country's decision adds pressure to the King and Queen Camilla's tour, announced last week, in which they will also visit the Bahamas and Guyana. They will use their trip to discuss the legacy of slavery and payment of reparations.
Ministers and new officials will swear loyalty to the state of Antigua and Barbuda. Its attorney general Sir Steadroy Benjamin said dropping the oath of loyalty was overdue.
'We will once and for all finally not be swearing to His Majesty in England, his heirs and successors in England,' he said.
Withdrawal of the King's name from the process of swearing in governments is a step towards removing the Royal Family from the affairs of the nation.
In 1981, Antigua and Barbuda declared independence from British rule but remained part of the Commonwealth, retaining the Queen as head of state.
However, led by republican prime minister Gaston Browne, the government has voted to remove the pledge to the British monarch. If it were to remove the British Crown entirely, the matter could be put to a public vote.
Antigua and Barbuda has dropped its pledge of allegiance to the King – two months before he is due to visit the Caribbean country (the King pictured in Bermuda in May)
But it is unclear which way a referendum would go, with some arguing support for republicanism is not as strong as the government claims.
During his trip, the King, who was seen yesterday with Camilla attending church at Balmoral, will discuss 'de-realming', in which countries stay in the Commonwealth without him as head of state.
In 2021, Charles gave a speech outlining his hope Barbados would stay a friendly country as Dame Sandra Mason became the first president and replaced the British monarch as head of state.
Antigua's decision comes after Grenada last year also removed its oath of allegiance. Not all Commonwealth nations plan to follow.
The King will also visit the Bahamas where there are no plans to remove him as head of state.