No senior members of the Royal family will attend Cop27 after it was confirmed the King and Prince of Wales will not travel to Egypt - despite their long-term campaigning on the environment.
The King, who was widely expected to go in person before the death of his mother, will not attend on the advice of the Government.
The Prince will also not attend the Egypt summit or send a message, concentrating instead on his Earthshot Prize.
Their absence will be a surprise to many environmental campaigners, after a full Royal family showing at Cop26 in Glasgow - with Queen Elizabeth II delivering a heartfelt message about saving the planet.
The King is said to be keen to find a way to contribute to the deliberations from afar.
The Sunday Times reported that Liz Truss objected to plans for the King to go to the Sharm El Sheikh gathering during an audience at Buckingham Palace last month.
A senior royal source said: "It is no mystery that the King was invited to go there. He had to think very carefully about what steps to take for his first overseas tour, and he is not going to be attending Cop."
On Sunday, sources maintained that the decision was taken jointly, after the palace sought government advice as per custom for overseas royal visits.
The Telegraph has previously reported that the King will continue to champion the environment while on the throne, choosing to "highlight" rather than outright "campaign" in concession to his new neutral constitutional role.
He spent decades as Prince of Wales arguing for further action on climate change. He delivered the opening speech at the landmark Cop21 in Paris in 2015.
His son William, who has now inherited the title, has also made the environment a cornerstone of his public work, founding the Earthshot Prize.
He too will not attend Cop27 and is not currently planning to take part from a distance, in line with government advice.
On Sunday Simon Clarke, the Levelling Up Secretary, told Times Radio: “It’s been clear this is a decision that has been made consensually between the King and the Government.
“That is a decision that has been made amicably, as far as I am aware, between the palace and the Government. The suggestions this morning that he was ordered to stay away are simply not true.
“I think it is very different when you are the host country for a major event like Cop to have the head of state involved, as opposed to the head of state going to what is an event being hosted in Egypt.
“It is the normal course of matters that this would be handled by the Government rather than by the monarchy.”
Ms Truss is "unlikely" to attend the summit, it has been reported.