EXCLUSIVE: Fresh Royal Feud Erupts as Heir Prince William is 'Running Secret Diary' While He 'Waits for King Charles to Die'

Prince William has opened up about his approach to his royal role, revealing: "I'm trying to do it differently, and I'm trying to do it for my generation."

And behind palace walls, sources tell RadarOnline.com the future British monarch is already carving this path – by maintaining a private calendar of engagements and quietly preparing for the day he ascends the throne, all while tension with his cancer-stricken father King Charles continues to grow.

The royal rift has intensified in recent months, with insiders claiming William, 41, and Charles, 75, are running entirely separate operations, with the heir to the throne refusing to coordinate even the basics of his schedule with his father's team.

"He's incredibly private and strong-willed," a palace flunkie said. "William's been keeping his official calendar under wraps – even from Charles' staff – because he doesn't want any interference. It's like he's already acting like the monarch in waiting."

While Charles remains king, despite his ongoing cancer battle, insiders say he is not ready to step aside – even as William begins to position himself for the next chapter of the monarchy.

"Charles has waited his entire life to wear the crown," a senior royal source added. "He's not going to let illness or his son's ambition get in the way of fulfilling his destiny.

"The reality is, Charles and William are rivals now. William isn't taking direction from Charles – not professionally and certainly not personally. They rarely collaborate anymore."

According to royal commentator Richard Fitzwilliams, Charles had hoped William would start absorbing some of his duties – particularly his 500-plus patronages.

But the Prince of Wales is charting a new course with the help of his wife Kate Middleton.

"William is focused on quality over quantity," a source close to the royals said. "He and Princess Kate want to support fewer causes, but dive deeper into the issues they care most about. It's about relevance, not tradition."

This divergence is evident in their approaches to royal life.

While Charles is known to be a tireless workaholic, often blurring the lines between public and private time, William is fiercely protective of his home life.

"He puts up firm boundaries," a friend of his and Kate's said, adding about his approach to their three kids: "He's determined to give Prince George, Princess Charlotte, and Prince Louis a childhood that's worlds apart from his own."

The unspoken issue that continues to hang over the monarchy is succession.

While the topic is rarely addressed directly, insiders say it is a major source of strain.

"It's a hugely sensitive subject," a courtier said. "They tiptoe around it, but everyone knows the day will come – and William is already getting his ducks in a row."

During a royal visit to Cape Town on November 7, William hinted at what his reign might look like.

"To give you more of an understanding around it, I’m doing it with maybe a smaller 'R' in the royal," he said.

The comment raised eyebrows among traditionalists – and reportedly irked Charles' more conservative camp.

And the friction is long-simmering.

Another insider added: "William doesn't want to be a carbon copy of his father. He's quietly building his own court, his own agenda, and his own rulebook. Charles knows it – and it's made things very tense."

While the king continues to undergo treatment, palace aides say he remains committed to his duties.

But William's behind-the-scenes maneuvering has only added to speculation about the future of the crown.

A royal source added: "He's not sitting around waiting. He's preparing for his moment – whether his father is ready or not."