Another bombshell book is to paint senior royal ­figures as dysfunctional and opportunistic.

The allegations are made by Duke and Duchess of Sussex loyalist Omid Scobie, who cites unnamed sources. His book claims Charles is not enjoying being King and alleges William is a hothead who employs the dark arts of publicity.

Royal author Margaret Holder said: “If Harry wants to heal the rift with his family, he needs to stop the victim agenda and start taking a more mature stance by accepting blame for his own role in the breakdown of family cohesion.”

She added: “Harry could be more protective of his family and tell sources who speak to Scobie to end any association with him.

“If people believe [he] speaks for Harry and Meghan, that is simply helping to damage the Royal Family and any chance of a reconciliation with the Sussexes.”

Endgame: Inside the Royal Family and the Monarchy’s Fight for Survival is due to be published in hardback in the UK on Tuesday this week.

Experts said that damaging revelations in it would reverberate throughout the next generation of royals and pit the Waleses’ three children against Harry and Meghan’s two.

Dai Davies, ex-head of royal protection for the Met Police, said: “This is clearly a hatchet job.”

He added: “This sounds like an attempt to drive a wedge between the King and William.”

Mrs Holder added about the book yesterday: “I don’t dispute his right to present the case for a modernised monarchy – on that I agree with him – but I do regret his quoted savaging of William and Catherine.

“Given the inside information Scobie appears to have from private correspondence between Meghan and Charles, I have to conclude he has a special relationship with the Duke and Duchess of Sussex.”

The allegations made in the book have been dismissed as another attempt to create a further chasm in a family already at war. Scobie contends they are a “reality check”.

Mrs Holder said: “That doesn’t mean he should continually stir the feud between the two brothers who should be locked in life through the shared tragedy of their mother’s loss.

“My concern isn’t that Scobie will bring down the monarchy, as he simply hasn’t got the power, but this repeated pattern of defending Harry and Meghan’s corner to please their supporters might spill over into the next generation of young royals with the Sussex children at odds with their Wales cousins.” In his latest book, Scobie writes on the Royal Family’s “fight for survival”.

He said at the weekend: “It would take a lot to dismantle the British Royal Family. But could William be the last King as we know it?

“Absolutely. The book isn’t hammering the final nail in the coffin. It’s just a reality check.”

Leaked extracts paint the Princess of Wales as “terrified to do anything more than grinning photo opportunities”. It was also claimed that William has been in league with Palace aides who dream up dirty tricks, using their contacts to portray Harry as emotionally fragile. William, heir to the throne, is painted as a cold and ruthless figure who cannot wait to succeed his father Charles – who he reportedly considers to be a transitional monarch.

Scobie claims William has a fiery temper that belies his soft public image, describing him as “reserved on the pitch but unpredictable” off it.

He said: “When something doesn’t suit him, his anger immediately escalates. He wants the job done and he has no problem with casualties along the way. The Prince of Wales is eager to ascend the throne. A real impatience is created around him.”

Scobie also claims that Charles, who inherited the throne from his late mother Elizabeth II in September last year, is jealous of William as he has come to accept his own reign will be merely transitional.

It is also said he resented Harry’s previous stratospheric popularity with the public and turned a blind eye while aides leaked details about his sons to the media in an effort to create a “great dad” narrative.

The book also suggests Charles thought his younger son was a “fool” for sanctioning last year’s fly-on-the-wall Harry & Meghan Netflix series.

It triggered a family row, while the book claims Charles told “lies” and William “screamed and shouted” after the Sussexes announced plans to quit public life for the US. Scobie claims Charles’s failure to speak to Harry after the series and the Prince’s interview with Oprah Winfrey proves he is incapable of handling constitutional crises. The hit documentary was followed by Harry’s memoir Spare, in which he described in searing detail his “incredibly painful” childhood.

He left Britain in order to break the “cycle of pain” on a “freedom flight” and now lives in California with his ex-actress wife and son Archie Harrison, four, and daughter Lilibet Diana, two.

The Prince said his family had been portrayed as “villains”, saying of senior royals: “They’ve shown absolutely no willingness to reconcile.”

Spare, the fastest-selling non-fiction book, reported incendiary claims including that irate William attacked Harry during a row. Endgame is to make further controversial claims about the relationship.

Most damning is the allegation that William did not like Meghan from the start of her relationship with Harry, and he distanced himself from his brother after the pair’s 2018 wedding in Windsor Castle.

Welsh-born Scobie, 42, said: “Meghan has made it clear that she never wants to be involved in the British monarchy again.”

The Daily Express contacted Buckingham Palace but by last night officials had declined to comment on any of the claims. The Duke and Duchess of Sussex distanced themselves from Scobie’s book and rejected suggestions of an affiliation to him.

The writer said: “Endgame is about the current state of the British Royal Family. It’s not ‘Harry and Meghan’s book’, I’m not ‘Meg’s pal’, the Sussexes have nothing to do with it, their story is a small part of a much bigger one.”

Mrs Holder said: “Even the catchy title harks back to a remark made in 2001 by the late Anthony Holden about Diana’s Panorama [interview] to the authors of Diana: Story of a Princess. Commenting on Tory minister Nicholas Soames’s attack on Diana, Holden said: ‘I thought that this was really the endgame now.’ Scobie clearly thinks it is.”