Prince Charles has been preparing for more than seven decades to take his place on the throne – and now that moment is imminent, Charles has confessed he is far from ready.
In an intimate mother-son exchange last month, shortly after the Queen's return from hospital, sources say Charles, 73, confided his fears to his 95-year-old mother, even going so far as to suggest passing the crown on to his son, Prince William.
"It was an incredibly raw exchange," says a palace insider.
"Having Ma'am in hospital triggers all kinds of protocol in the event of her passing – and Charles was affected by it.
"His time at the climate summit reaffirmed what he really wants to do – activism."
There's no doubt the younger and arguably more popular, William, 39, is more than capable of stepping into the role of king.
"Charles pointed out that William has Kate – and unlike Camilla, Kate's always been adored by the public and could be a more effective queen," adds the insider.
"He also argued from a cost-saving perspective, isn't it best to pay for just one coronation instead of two in the space of a few years?
"Charles isn't as strong as he was before his bout with COVID last year and the Queen did expect this.
"It isn't the first time he's come to her with self-doubt about stepping into her shoes.
"It's hard for her to not get exasperated at Charles' insecurities, but it's also her duty to ensure a meltdown-free handover when she does leave this earth."
Yet Charles' insecurities couldn't have come at a worse time for the duty-bound Queen, who has proven to once again be a restless patient, with her most recent health struggles barely slowing her down.
"She's always had little time for emotional delays and the older she gets the more that's apparent," adds the insider.
"She does worry about Charles, but she has also done her best to put a good team around him, in preparation for when the time comes.
"But duty always comes first and the Queen is more aware than anyone that she has no time to waste."