Prince William vs. Prince Harry: Prince of Wales' 'Lost Trust' in Montecito Duke Can Be Fixed 'On One Condition' Only

The trust between Princes William and Harry is likely "eternally lost" thanks to the latter's "endless attacks" on the monarchy. The rift is so severe that even after nearly two years of estrangement, the royal siblings allegedly could not even look at one another at Lord Robert Fellowes' memorial on August 29.

"Since we learned that Harry had made this unannounced visit, I’ve been speaking to people about… the chances of a reconciliation between the brothers, but everyone really has made the same points that it won’t happen until Harry and Meghan really apologize for everything they have said," royal editor Richard Eden shared.

This "one condition" requirement follows the Prince of Wales' reply to his brother's message of support after Catherine, Princess of Wales revealed she was battling cancer, was reportedly "thick with frost."

"Harry and Meghan have been in contact with William, but their private message was simply one of sympathy and didn’t include any suggestion the brothers should make up and let bygones be bygones or that Harry should fly back to the U.K. soon," royal author Tom Quinn revealed.

"There is just too much ill feeling for that," he added. "William, who is still hurt by everything Harry has said in the past, has responded, but the response is very much engineered by the palace, and it’s hardly the kind of warm, informal response you would expect from one brother to another. It's more like the sort of communication you would get between two slightly wary diplomats."

This revelation comes after news highlighting how King Charles III is busy as Britain and several other nations' head of state, but the monarch is reportedly dedicated to mending the rift between his sons.

That rift sounds like one that's going to be very difficult to mend," journalist Nigel Nelson told an outlet. "If it is mendable, who would be in a better position to mend it than their father?"

The King's death will immediately make William the new monarch, and reports now reflect a potential Montecito meltdown when the news one day hits.

"Because what would the repercussions be if Prince William pushed you out of the fold?" royal expert Kinsey Schofield told an outlet.

"I do think he would write about his family again," she added. "He was waiting to publish a book after [Queen Elizabeth died]. Originally they were saying there was going to be another publication after the [late] Queen died. I suspect that maybe he would release a book after his father passed away especially if Prince William continues to keep him at arm's length."

Other reports suggest the future king has decided it is time to "fully" sever all contact with his youngest brother. With the reception Harry got from his future king on August 29, this seems to be a confirmed certainty.

Daily Express reported on Eden's remarks.