Royal War – 'Death's Door' King Charles and Heir Prince William's Secret Power Battle Exposed – As Camilla Desperately Tries to 'Future Proof' Position

King Charles' health has been a focus of Royal woes, but insiders claim a storm has been brewing behind closed doors.

RadarOnline can reveal a power struggle between Charles and king-in-waiting Prince William has reached a fever pitch, with Queen Camilla getting involved.

An impatient William, 42, is said to be making it clear he intends to modernize The Firm when he takes over the throne.

A royal insider said: "Charles' lifelong plans for his reign are already being eclipsed by William's fresh plans."

During his November trip to South Africa, William told reporters: "I'm trying to do royalty differently – and I'm trying to do it for my generation. I'm doing it maybe with a smaller 'R' in the royal."

While it's unclear if William's promise was intended as shade against his traditionalist father, 76, sources claimed his vision for the monarchy's future has added to the tension between the father-son duo.

One source explained: "Their dynamics have shifted.

"Charles has wanted to be the monarch for decades. Even though he's battling cancer, he's not letting that get in the way of his desire to be a dynamic leader."

Meanwhile, a separate insider claimed: "William is already preparing for his ascension.

"Like his father, he takes being a success in the royal role very seriously."

As RadarOnline.com reported, a source said: "Charles is a workaholic – he has accumulated over 500 royal patronages that he and Queen Camilla support."

But William has publicly stated his cancer-stricken wife, Kate Middleton, 42, and their children – Prince George, 11, Princess Charlotte, nine, and Prince Louis, 6 – will remain his top priorities.

A royal insider added: "(William) also take on fewer patronages too and focus on causes most important to him and Catherine, like environment, mental health, and homelessness.

"William doesn't want to waste money or time on fringe projects. He wants it to be earmarked for his homeless projects, for example."

Another source of growing tension between Charles and William is said to be their dramatically different attitudes towards royal renegade Prince Harry.

While one source claimed, "Charles will always leave the door open for his youngest son", others said William has grown frustrated with a lack of decisive action in dealing with his younger brother five years after he and wife Meghan Markle gave up their full-time royal duties to move to the U.S.

The insider added: "William is frustrated that his father refuses to take a more hardline approach. He also wants the situation with Prince Andrew and his habitation of Windsor's Royal Lodge resolved now."

While Charles and William certainly share a close bond, they're also said to be royal "rivals".

An insider explained: "The longevity of the monarchy relies on its popularity with its subjects.

"William, like his mother Princess Diana, before him, had always enjoyed public approval and affection. And Charles is well aware that some wanted the line of succession to skip him entirely when Queen Elizabeth II died, with William crowned as King instead. He was deeply hurt by that chatter."

As a result, William and Middleton have been forced to tread lightly when it comes to openly discussing Charles' succession, despite their ever-present need to be ready to take the throne, especially given his health issues.

When Charles' cancer diagnosis made headlines in February, William immediately sprang into action.

A source previously told us: "They've agreed on what they will focus on at the start of his reign and the funeral plans for his father."

Since then, William has kept his father updated out of courtesy.

The source added: "But (Charles) does not feel comfortable speaking about it at length."

Now, it's become evident Charles and William share very different views on how The Firm should be run.

The source said: "William and Catherine are preparing to run a modern reign when the time comes – and Charles knows it.

"He wants his son to be ready, but he doesn't want his legacy to be swept away either. It's a delicate situation.”