The Royal Family’s future relies on William and Charles having a ‘joint approach’ when it comes to Harry’s visits, a royal expert has claimed – suggesting it’s clear the Prince of Wales is ‘concerned’ how the Duke of Sussex’s presence could ‘overshadow the valuable work the monarchy is doing in the media’.

Speaking to the Daily Mail, author Richard Fitzwilliams said that while the King most likely wants to connect with his grandchildren Archie, seven, and Lilibet, five – who are an ocean away in Montecito – the heir is more wary.

‘The most disastrous thing that could happen to the monarchy would be a falling out between King Charles and Prince William, who, together with his family, is its future,’ he continued.

‘We know the King understandably wanted to see his grandchildren and the Sussexes have subsequently been silent personally, but briefings have not ceased.

‘They obviously plan future visits. They want the King to see more of his grandchildren which is totally understandable. Things will undoubtedly be better arranged regarding accommodation and, hopefully, security in future.’

In turn, Richard added, it may result in the King’s possible attendance at next year’s Invictus Games in Birmingham.

‘After all, he is the head of the armed forces and it undeniably is a valuable military charity.’

The expert also shared: ‘William showed public disdain for his (wayward) brother by playing polo with Catherine’s support on the day the Sussexes met the King and Queen.

‘If this was a one-off, few could object.

‘However, it is clearly part of a strategy. Harry and Meghan’s royal links mean everything, and Harry is wonderful with children.

‘Whilst appreciating his father’s approach, William is likely to be concerned about the effects of future visits. These are likely to overshadow the valuable work the monarchy is doing in the media.

‘It would be best if they happened privately with no one knowing and great progress might then be made, though that does not tend to be the Sussexes’ way.

‘Also, the idea of a form of “half in half out”, which Queen Elizabeth rejected, could be revived, according to reports, but it might be difficult to agree how this could be handled in practice.’

Richard stressed, however, that William and Charles must present a united front as the King’s future relationship with Harry progresses.

‘When there are disputes between families, reconciliation should always be welcomed. However, it often comes at a cost,’ he explained.

‘The Royal Family will bear in mind that the 30th anniversary of Diana’s death is coming up and Netflix would clearly like first refusal on anything the Sussexes were involved in to commemorate this.

‘There is a lot to play for and obviously we must hope one of the world’s most public family disputes is gradually resolved.

‘However, it is essential for the future of the monarchy that the King and Prince William agree a joint approach – both publicly and privately – on how this should be handled.

‘The optics of the way the King and William are handling this issue are fuelling reports, backed up by royal author Tina Brown last September, of serious divisions between them.

‘Since it is essential for the future of the monarchy that they speak with one voice on substantive issues, this is damaging for the monarchy and confusing for the public.’

He added: ‘Since the institution cannot afford deep divisions between them, perhaps Queen Camilla and Catherine will play a part in ensuring that, even if their priorities are different from the Sussexes’, that they present a more united front publicly.

‘If it was ensured that future visits by the Sussexes were private, that would obviously help.’

Ms Brown also said that Charles’s ‘alternation from his exasperating younger son is a constant heartache, made more painful by the fact that his paternal relationship with William, who was staunchly against his visit, is civil at best’.

She also suggested that ‘many in William’s camp considered the Highgrove rapprochement a reward for Harry’s manipulation and emotional blackmail’.