The move, confirmed by senior Royal Navy sources, anticipates that the outcome of Harry’s 12-month review will find “no reason to alter current arrangements”. The Duke of Sussex was appointed Captain General of the Marines in 2017 when his grandfather Prince Philip stepped down after holding the post for 67 years.
The decision to formally replace him will come as a blow to Harry who is said to have hoped to resume his ceremonial duties despite moving to the US with wife Meghan.
It comes as a new book, Battle Of Brothers, claims to expose the depth of Royal Family anger after Harry and Meghan’s decision to step down.
The Duke of Cambridge was so infuriated that he refused to dine with Harry alone before a summit with the Queen, it was claimed.
The Queen also felt the Duke and Duchess of Sussex were “erratic and impulsive” in making their departure, the book by royal biographer Robert Lacey said.
While William currently holds titles across the Armed Forces, his only major command appointment is as the Colonel in Chief of the Irish Guards. And the Marines feel the future king will be a boost for morale and recruitment.
A source said: “The Duke of Cambridge has been approached with a view to taking on the role of Captain General.
“ There is a real sense that, should he accept, he would offer the Corps exactly what it needs at this point in its history.
“Our understanding is that he is keen to take up the appointment.”
In March, Harry reportedly told the Commandant General Royal Marines, Matthew Holmes, he was “devastated” at having to step down, adding: “I feel I’m letting people down, but I had no choice”.
It comes as Prince William’s three children have been quizzing conservation king Sir David Attenborough about nature for a new programme made by the Duke.
Princes George and Louis and sister Princess Charlotte all asked Sir David, 94, about animals.
The cute question and answer session was filmed at Kensington Palace – the family’s official London residence – for a show William put together about conservation.
In it, the proud dad, 38, reveals that all three of his youngsters love the outdoor world. His eldest son George, in particular, he said, “is like a caged animal” if he is stuck indoors for a long time.
The footage was released yesterday by the Duke and Duchess of Cambridge after Sir David paid them a visit last week.
During the trip he gave Prince George a fossilised shark tooth. And it was seven-year-old George who asked the first question for the programme, which will be broadcast on ITV tomorrow night.
Dressed in a casual red and navy T-shirt, he confidently said: “Hello David Atten-borough, what animal do you think will become extinct next?”
Sir David, who looked delighted throughout the chat, said: “Well, let’s hope there won’t be any because there are lots of things we can do when animals are in danger of extinction. We can protect them.”
He then mentioned the moment his TV career took off, saying: “About 40 years ago I was with some mountain gorillas in the centre of Africa – mountain gorillas were then very, very rare, only 250 of them left – and we showed pictures of them on
television around the world, and people thought how terrible it would be if these became extinct.
“So they subscribed lots of money and lots of people came to help, and now there are over a thousand of them.
“So you can save an animal if you want to and you put your mind to it.
“People around the world are doing that, because animals are so precious, so let’s hope there won’t be any more that go extinct.”