A royal author believes inviting Prince Harry and Meghan Markle to Balmoral Castle this summer was never a realistic consideration.

The Prince of Wales is set to join King Charles at Balmoral this summer (Image: Getty)

In a major snub to Prince Harry and Meghan Markle, a royal author believes the royal duo’s invite to Balmoral this summer was never a realistic condition.

It comes as King Charles and his eldest son, Prince William, reportedly came together and decided things were just too challenging following a demanding year for the firm with both the reigning monarch and Princess Kate undergoing treatment for cancer.

Some royal observers believe the family gathering in Scotland represented the perfect opportunity to extend an invite to Harry and Meghan, but it is understood the Sussexes will not be returning to the UK.

Royal author, Tom Quinn, told the Mirror the situation is the “last thing” the family needs. he said: “With Kate and Charles in a difficult place, the last thing the family needs is Harry at Balmoral. Everyone knows that it couldn’t be done without also inviting Meghan and that is a step too far.”

Prince William and his family will be making the journey to Balmoral (Image: Getty)

The author continued: “Meghan has always been seen as the main driving force behind Harry’s public attacks on the family. William and Charles know that inviting Harry without Meghan is just to give Harry another subject for the sequel to Spare that Harry is writing.”

Prince Harry is thought to be penning a sequel to his memoir, Spare. The Duke said shortly after the book’s publication that “there could have been two books”, telling the Telegraph: “The hard bit was taking things out.”

Prince William and his family are set to join the Royal Family for their traditional summer trip, which will mark Kate’s longest journey since her diagnosis.

In June, Kate shared an emotional message with the public, saying she was “not out of the woods yet” and had “good days and bad days”, adding that her treatment would continue for “a few more months.”

Harry and Meghan are thought not to be joining Balmoral this year (Image: Getty)

Prince William has been enjoying his holidays in Balmoral ever since he was a child and Princess Kate began joining him once they married in 2011.

The estate has played an important role in William’s life as it is where he has some of his happiest childhood memories, but also his saddest. William and Harry were at Balmoral in 1997 when they received the tragic news their mother Princess Diana had died.

He once told the General Assembly of the Church of Scotland: “Scotland is a source of some of my happiest memories but also my saddest. I was in Balmoral when I was told that my mother had died.

“Still in shock, I found sanctuary in the service at Crathie Kirk that very morning and in the dark days of grief that followed I found comfort and solace in the Scottish outdoors.

“As a result, the connection I feel to Scotland will forever run deep. Alongside this painful memory is one of great joy because it was here in Scotland 20 years ago this year that I first met Catherine.”