Prince Harry's strained relationship with King Charles III has worsened as the Duke of Sussex pursues a legal battle over the loss of his U.K. security protections and skipped an opportunity to visit his ailing father during a recent trip to London, according to sources familiar with the situation.

The Duke, 40, returned to the U.K. on April 6 to attend a two-day appeal hearing concerning the suspension of his taxpayer-funded security detail. Despite King Charles, 76, being in London for cancer treatment at the time, the two did not meet. Royal expert Richard Fitzwilliams told Us Weekly, "At the moment, Harry does not seem to have a relationship with his father at all. It's truly sad."

Sources told the Globe that Harry's wife, Meghan Markle, dissuaded him from seeing his father, with insiders saying, "Harry would have liked to pay his dad a visit, but he didn't - and everyone is saying it was his fear of upsetting Meghan that held him back." The former actress has not returned to the U.K. since Queen Elizabeth II's funeral in 2022.

While in London, Harry described feeling "exhausted and overwhelmed" following court proceedings and claimed the public would "be shocked" by what had been disclosed behind closed doors. His attorneys argued the decision to downgrade his security was unjust and lacked a full threat assessment, citing threats from neo-Nazi groups and al-Qaeda.

The breakdown of communication between father and son has been fueled by mutual distrust. Royal insiders said Charles has not responded to Harry's messages and sees no avenue to intervene in the decision made by RAVEC, the executive body responsible for the protection of public figures. "Prince Harry doesn't seem to understand that Charles can't get involved," one source said. "It's between Harry and the Home Office."

Harry's dissatisfaction has fueled speculation that he is considering new ways to voice his grievances. Insiders allege he is plotting either a second memoir or a tell-all podcast, potentially revealing further private royal family matters. "The more he's ignored, the angrier he gets," a source said.

The ongoing tension is compounded by Harry's growing public profile. Meghan recently launched her new podcast, Confessions of a Female Founder, and the couple's Netflix series, With Love, Meghan, was renewed for a second season. Meanwhile, Harry made a surprise trip to Ukraine on April 10 to meet wounded soldiers, which royal insiders criticized for overshadowing Charles' official state visit to Italy with Queen Camilla.

According to Fitzwilliams, the royal family remains deeply wary of Harry. "In a nutshell, The royal family does not trust Harry," he said. There is concern that "something he says privately could be used in court ."

Adding to the complicated dynamic is Harry's insistence that security protections are critical given the history of his mother, Princess Diana, who died in 1997 after being pursued by paparazzi. "A pivotal part of Prince Harry's motivation is the intense feeling that he and his family are the victims of injustice," Fitzwilliams said.

While Harry awaits the outcome of his appeal - expected after Easter - sources say there are no ongoing communications between him and King Charles. "Charles loves his son," royal historian Marlene Koenig said. "But at this time, he and his advisers prefer the tough love treatment."