The Duke of Cambridge has confessed he was worried when the Prince of Wales was diagnosed with Covid-19 and says the family are doing “everything we can” to protect the Queen and Duke of Edinburgh.

William’s admissions were made in an interview with his wife where they also joked about the challenges of home schooling their children and the “ups and downs” of living in lockdown.

And the couple revealed like the rest of the country they are staying in touch with members of their family via video calls.

The duke also praised veteran fundraiser Captain Tom Moore who has raised millions for the NHS walking lengths of his garden describing him as an “absolute legend”.

Talking about his father, who suffered from mild symptoms of Covid-19 and recovered after a period of self-isolation, William told the BBC: “I have to admit at first I was quite concerned, he fits the profile of somebody, at the age he’s at, which is, you know, fairly risky, and so I was a little bit worried.

“But my father has had many chest infections, colds and things like that over the years and so I thought to myself (if) anybody’s going to be able to beat this it’s going to be him.”

The duke said he was reassured by doctors and friends who advised him by the time Charles reported his symptoms he was “probably past the worst of it”, and his mind was put at rest after speaking to his father but at his age of 71 “you do worry a bit more”.

William said that as a “mad walker” his father found it hard remaining inside during his seven-day isolation period: “He loves his walking. So I think he found it quite difficult, especially also, I think, with his mental health, being stuck inside and not being able to go for walks.”

The Queen, 93, has been staying at Windsor Castle, with the Duke of Edinburgh, 98, as a precaution for a number of weeks and the duke said he also has concerns for his grandparents.

William said: “And obviously I think very carefully about my grandparents – who are the age they’re at, we’re doing everything we can to make sure that they’re isolated away and protected from this.

“But it does worry me, what’s going to happen to a lot of the vulnerable, high-risk people who are going potentially to have to isolate away for quite some time.”

William and Kate spoke to BBC News via a video link from their Norfolk home on Thursday and were casually dressed for the informal chat, a rare joint interview.

Asked about life in lockdown, the duchess said: “It’s been yes, ups and downs, probably like lots of families.

“Somebody gave me some very good advice pre the holidays – (it) was to put in structure, so we’ve kept to a pretty strict routine.”

The couple have three young children at home, Prince George, aged six, Princess Charlotte aged four, and Prince Louis, who will celebrate his second birthday next Thursday.

Kate joked she felt guilty for keeping a makeshift classroom up and running during the Easter holidays as the country remained in lockdown during the outbreak.

She said: “Lots of home schooling, which is challenging,” she added with a laugh “don’t tell the children we’ve actually kept it going through the holidays, I feel very mean.

“It’s just having that bit of structure, actually.

“It’s great, there are so many great tips online and fun activities you that can do with the children so it hasn’t been all hardcore.”

The duke revealed that older members of his family are not far behind their younger relatives when it comes to video calling each other.

William said: “We’ve done many a family thing, we’ve been talking to all the family online.

“And it’s been a really good way of keeping in touch and seeing each other.”

Both the Queen and Philip are known to embrace modern gadgets, with the head of state using the internet to keep in touch with her grandchildren before the coronavirus outbreak.

The duke added: “As you can imagine, the younger generation are a little bit more tech savvy, but only just, I think we’re getting there now.

“The family are getting a little bit more used to be able to contact each other and pressing the right buttons and not dropping the computer half way through.”

Kate added: “That’s so true, and actually your father and my parents and our families and things like that have really loved keeping in touch with the children, because it’s really hard at times, particularly over family times like Easter not seeing each other.

“It gets a bit hectic, I am not going to lie, with a two-year-old.”

The duke quipped: “For some reason he sees the red button and he always wants to press the red button.”

William also praised fundraiser Capt Moore.

The duke described the 99-year-old as an “absolute legend” and has written to him and made an undisclosed donation to his appeal.

The royal added: “It’s incredible, I did see it on the news the other night and I thought good on him.

“It’s amazing and what I love also is that he’s a 99-year-old war vet who’s been around a long time, knows everything and it’s wonderful that everyone kind of has been inspired by his story and his determination.”