The Duke of Sussex will come face-to-face with the Queen on Monday amid Buckingham Palace fears that he and his wife could go public with damaging accusations about the family if they do not get what they want.
As the Queen, the Prince of Wales and the Duke of Cambridge join forces to confront the Duke, 35, for the first time since he announced plans to walk away from his role, the threat of a “no-holds barred” television interview loomed large.
The crisis summit taking place at Sandringham is expected to last several hours as the family combs through the various scenarios that could form a blueprint for the Sussex’s “progressive” new roles.
Prince Charles was due to travel back from Oman on Sunday night for the family summit having flown out to attend a condolence ceremony following the death of Sultan Qaboos bin Said al Said.
The Queen has made it clear she wants the “Sussex situation” as it has become known, resolved within days to prevent further damage to the monarchy.
The Duke of Edinburgh, 98, is said to have been left “deeply hurt” by his grandson’s decisions and is angry at their “lack of respect”.
The Duke is “with the Queen at Sandringham and supporting her” a royal source said, although he is not expected to take part in the summit. The Duchess of Sussex is expected to dial in from Canada.
Buckingham Palace aides fear the Duke and Duchess, 38, could prove problematic for the institution if they are allowed to cut loose and are not kept on side.
Tom Bradby, the ITV journalist and a friend of both Prince William and Prince Harry, warned on Sunday that the Sussexes were considering a set-piece television interview in which they reveal their reasons for stepping back from the family.
"I have some idea of what might be aired in a full, no-holds-barred sit down interview and I don't think it would be pretty,” he wrote in the Sunday Times.
While Bradby did not expand on the concerns the couple could voice, courtiers fear they might brand the royal household racist and sexist.
A royal source said there was "concern" behind palace gates about an interview that was beyond the press office's control.
"Just look at what happened with the Duke of York on Newsnight,” they said.
The Duke of Cambridge, who was said to have been upset when his brother appeared to confirm rumours of their rift in an interview with Bradby last year, is said to be particularly concerned that the couple may be planning to "sound off".
"That's why these negotiations are so delicate,” the source added. “The last thing the royals want is any acrimony making it onto the airwaves in a way the palace can't control".
Other royal insiders have suggested the Sussexes are preparing to reveal more about the “challenges” they have faced through friends and sources in the coming weeks.
Separately, one of the Army’s most senior former officers today urges the Duke of Sussex to "put Queen and country first", while James Glancy, a former Captain in the Royal Marines Special Boat Service, said he and many military colleagues would not raise a toast to the Duke, who is their Captain General, if he tried to earn money from his royal position with commercial ventures.
With the cost of security set to be one of the biggest sticking points of the Sandringham discussions, Emily Thornberry, the shadow foreign secretary, also insisted that the British taxpayer should continue to fund it because the Duke “has done great service” as an Army officer.
The Queen put on a brave face as she attended church on the Norfolk estate yesterday. Dressed in a camel-coloured coat and hat, and wearing a hearing aid, she waved to the crowds as she arrived by car.
Asked how the 93-year-old monarch was, her grandson, Peter Phillips, 42, briefly hesitated before telling onlookers: “Alright.”