"Finding Freedom," a biography about Prince Harry and Meghan Markle written by Omid Scobie and Carolyn Durand, makes startling claims about the couple's relationship with the rest of the British royal family.

According to the biography, Prince Harry felt his father Charles, the Prince of Wales, valued his own public image above their father-son relationship. The royal also reportedly grew "frustrated" that he and wife Meghan Markle "often took a backseat" to other members of the royal family.

An extract of the biography released in The Sunday Times states that while the Duke and the Duchess of Sussex "respected the hierarchy of the institution, it was difficult when they wanted to focus on a project and were told that a more senior ranking family member, be it Prince William or Prince Charles, had an initiative or tour being announced at the same time — so they would just have to wait."

The book also claims that Harry considered his elder brother William a snob for telling him that he was "blinded by lust" over "this girl" Meghan and should take things slow.

The Duke of Cambridge reportedly told Harry not to "rush this" and "take as much time as you need to get to know" the "Suits" alum. The book also claims that other royal family members also voiced concerns about the former American actress, while palace insiders described her as "Harry's showgirl" who came "with a lot of baggage."

"Take as much time as you need to get to know this girl," William told Harry, who considered the choice of the words "this girl" to be condescending.

The book also describes in detail the equation between sister-in-laws Meghan and Kate Middleton, which has been under scrutiny of British media and public ever since the former actress married into the royal family. The book said the "duelling duchesses" were "never really friends" and had little in common. However, the stories that Meghan drove Kate to tears at her wedding over whether Princess Charlotte should wear tights were dubbed "ridiculous and false."

The book suggested that Meghan and Kate were "a little stressed" during the fitting but there were no tears involved. "Some of the children weren't cooperating, and there was a lot going on. Everyone tried to help where they could, but it's never easy with kids at fittings. There were no tears from anyone," a source present at the fitting was quoted in the book.

The British royals
Rumours that all was not well with the Sussexes surfaced in October when Harry, sixth in line to the throne, admitted that he and William were "on different paths" and had good and bad days in their relationship. Photo: AFP / Paul ELLIS

Co-authors Omid Scobie and Carolyn Durand have insisted that "all information" in the anticipated book which covers Sussexes' dramatic departure from 'The Firm' has been verified by "at least two sources." The book published by Harper Collins is expected to hit the shelves on Tuesday, August 11.

Prince Harry Meghan Markle British Royal Family Prince William