Some charities feel confident they will still benefit from their links with the Duke and Duchess of Sussex, even after they have officially cut their ties as senior royals.

Map Ives, director and founder of Rhino Conservation Botswana, said he has already been told by an official in Harry’s office that the duke “wants to continue” his work with his organisation.

Mr Ives said: “If anything our relationship should get stronger.

“Yes, he is going to have to go out and earn some money but he has a personal understanding of biodiversity and about the health of the planet which leads him to want to be involved and want to help us with awareness.

“The addition of someone like Harry helps us to get the word out about what we are doing. We need awareness and appreciate support from people like that.

“If he had withdrawn as our patron or supporter I would have felt it personally myself because he is a very nice man but I am glad he is not going anywhere.”

Harry is the patron of WellChild, the national charity for sick children. A spokesman said: “They have already said they are going to honour their patronages.”

WellChild’s chief executive Colin Dyer said the charity is “privileged” to have Harry on board, adding: “The amazing support and hard work of the Duke and Duchess is always very much appreciated by everyone at WellChild.”

The couple have also announced plans to set up their own charitable entity.

Having served in the British Army for 10 years, Harry’s charity work has included campaigns to raise awareness of the challenges faced by service personnel who have switched to civilian life. His interests also include  sport, mental health awareness and African conservation.

Meghan’s patronages reflect an interest in the arts, access to education, support for women and animal welfare. They include the National Theatre and the Association of Commonwealth Universities, which were handed to her by the Queen.

She also took on the patronage of animal charity Mayhew and Smart Works, which helps unemployed women and for which she later designed a collection of clothes.

PR expert Mark Borkowski believes the couple will still have immense pulling power in the charity sector, but noted: “Whether they will become as interesting for charities going forward, I don’t think so, but they will carry a lot of chic and interest with them but sustaining that for 10,20,30 years is going to be difficult.”

He said: “They can raise a lot of money. They can make a lot of money and they clearly have an ambition and a purpose.  This is a significant move into another world and we haven’t seen that since Edward and Mrs Simpson.

“I think they (Harry and Meghan) are significant personalities in their own right now and wherever they go they will have press attention, the cameras will follow them. It’ll be talked about.

“So that’s not going to change and if anything, by not being connected to the Royal Family, not having the HRH monikers on it, they are doing something incredibly disruptive but they won’t immediately lose their sheen.”