Prince William is gearing up to return to public work after enjoying his annual summer break with wife Kate Middleton and their three children, Prince George, Princess Charlotte and Prince Louis.

The Prince and Princess of Wales are currently enjoying a relaxing holiday at Balmoral, where the royals have traditionally spent their summers since the reign of Queen Victoria.

This year’s summer break comes after a tough start to the year for the family following King Charles’ and Kate’s cancer diagnoses, which were announced publicly in February and March respectively.

And while many royalists will be looking forward to seeing the heir to the throne return to public duty, it is claimed that there are two people anxious about his next moves – his brother Prince Harry and sister-in-law Meghan Markle.

A source says the couple, who stepped down as senior working members of the Royal family in 2020, are “fretting like crazy” over how William’s new role will affect them, and whether they may lose their titles for good.

The source tells Closer, “They’re following the latest developments as closely as they can, even though communication is minimal if not non-existent as far as updates from the Firm. On one hand Harry is devastated and worried about his father’s declining health, but there’s also a huge amount of panic because William’s now stepping up and being entrusted a whole lot more. That spells nothing but bad news for the Sussexes as [William] would almost certainly double down on keeping them in exile, plus it’s common knowledge he’ll want their titles stripped and a zero-tolerance approach implemented as policy. They’re very alarmed at what the future holds, and with good reason.”

King Charles is handing over more and more responsibility to his eldest son as he continues to be cautious in his return to work following his cancer diagnosis – including the title of Colonel-in-Chief of the Army Air Corps, a position he had held for 32 years.

William also presented the men’s FA Cup trophy to champions Manchester United back in May, a job held by the king last year.

William will return to royal duties on 5 September to visit the Homelessness: Reframed exhibition at the Saatchi Gallery in London, Kensington Palace has announced.

He is expected to meet artists whose work is featured in the exhibition and people whose experiences have inspired the artwork. William will also meet with photographer Rankin, who produced the art and previously shot the late Queen Elizabeth II to mark her Golden Jubilee in 2002.

William’s relationship with his younger brother Harry is as fraught as ever, with him remaining stubborn despite Harry’s reported attempts to call a truce.

The source continues, “The relationship between Harry and William isn’t getting any better, despite all the efforts Harry’s made to extend an olive branch it’s very clear William isn’t going to budge. And the odds are the more William’s power increases the more estranged they’re going to be. They’ve already been cut off from invites and information, and William’s made it very clear that there’s no forgiveness on his part. It’s pretty likely at this point that even a grovelling apology wouldn’t do much to sway him because he’s just got so much resentment towards Meghan and Harry for what they’ve put the royal family through. As everybody knows, he finds their behaviour absolutely unforgivable.”

William and Kate were reported to be less than impressed by Harry and Meghan’s tours of Nigeria and Colombia earlier this year, which – despite not being official royal tours – were set out to look so.

Harry was reportedly left “embarrassed” following their tour of Colombia earlier this month after intense backlash by royal fans.

Our source adds, “Before King Charles’ ill health, everyone was under the assumption that it would be many years before William took the Crown, but the word coming out of Buckingham Palace is that it could be much sooner. And, in the meantime, while the King tries to get better, he’s understandably delegating quite a lot of responsibilities to William, who’s more than happy to take the baton, so to speak. And that raises panic for the Sussexes, not only because they’re bound to be pushed further and further away, but also because William is very against them keeping their royal titles. At the end of the day, losing their titles would be an absolute gut-wrenching disaster for them from a branding point of view, as well as a personal heartbreak for Harry.”

Harry and Meghan have continued to use their titles of the Duke and Duchess of Sussex for business purposes, including Meghan’s latest venture, American Riviera Orchard, which has failed to get off to a flying start.

“Meghan’s doing her best to help Harry stay calm and urging him to stay focused on the present and all they’ve got but no doubt this is a big worry for her too,” the source continued. “They’re still presenting themselves as the Duke and Duchess of Sussex, using those titles affords them a lot of opportunity that they wouldn’t otherwise get.

“The faux royal tours they’ve been doing depend on those titles so no doubt those would dry up. Which of course would please William to no end. He finds it reprehensible that they’ve undermined the monarchy so blatantly and yet they have no qualms about using their titles for their own gain, it’s no wonder he wants to strip them of those titles.”

But, despite their fractured relationship, it is said that it is the king himself that is allowing Harry and Meghan to continue to use the titles – something which will no doubt change once William takes the throne.

Charles has been an advocate of “slimming down” the royal family in the future, a model which William is also looking to adopt.

“The only thing standing in [William’s] way right now is Charles, once he’s fully in charge there’s nothing to stop him from following through, by all accounts Meghan and Harry are right to be worried.”