Prince Harry “still doesn’t get” why he’s being excluded from the royal succession plans, an expert has said.

The Duke of Sussex has made it clear that he is ready to help out his family following the King’s cancer diagnosis and treatment but he has thus far not been brought back in the loop.

A royal expert has said that the slimmed-down monarchy and Harry’s 2020 step back from being a senior royal has left him out in the cold.

Royal expert and author Tom Quinn told the Mirror: “It’s all about who’s going to be in and who’s going to be out and Harry is definitely out, but he still doesn’t completely get it. He’s like a naughty boy who always thinks he will ultimately be forgiven.

“The royals don’t regret slimming down the monarchy because, although King Charles’ cancer has increased pressure on the other working royals, a slimmed down royal family plays well with the public – they are seen to be managing despite their difficulties.”

Mr Quinn said the King’s succession planning has been brought forward by five years.

He said: “Because King Charles has cancer, succession planning is taking place right now – at least five years earlier than originally envisaged and it is focused on getting William and Kate up to speed.”

This comes as a new crisis emerges around the Princess of Wales’ time in hospital in January for abdominal surgery.

Hospital bosses have launched a probe into claims her confidentiality was leaked with at least one member of staff said to have been caught trying to access her private medical notes.

A source told The Mirror: “Prince Harry is keen to come over and offer his help to the family. The Princess of Wale’s health woes and now the hospital ‘leak ‘crisis is a concern for the whole family – including Harry.”

“It is a very sensitive matter, but Harry wants his family to know he is ready to step in and be of support. It’s a tough time for them all with King Charles’ cancer diagnosis but Harry is keen, now, more than ever to start moving forward and to rebuild damaged relationships.

“There is a lot of hurt between them all, but at the end of the day they are family. They all used to be so close, and Harry hasn’t forgotten the team they once were.

“Harry has offered his support and hopes they can come together as much as possible to support each other through this very difficult time for the family.”