Britain's Prince William and his wife Kate Image Credit: REUTERS

The Duke of Cambridge has admitted fatherhood has made him cry far more often and he finds himself worrying about “not being around to see your children grow up”.

The Duke, who lost his mother Diana, Princess of Wales, when he was 15, said he tends to “well up at the smallest little things”, after the birth of his children Prince George and Princess Charlotte made him more emotional. Meanwhile, Prince Harry disclosed the Royal family “love it” if official visits go wrong as it makes them more memorable, while the Prince of Wales joked he is “past my sell-by date”.

The princes were talking to TV presenters Anthony McPartlin and Declan Donnelly for an ITV documentary about their father’s charity, the Prince’s Trust.

Asked if fatherhood has changed him, the Duke said: “I’m a lot more emotional than I used to be. Yeah, weirdly. I never used to really get too wound up or worried about things, but now the smallest little things can get — I can feel — you well up a little bit more.

“You get affected by things that happen around the world or whatever a lot more I think as a father, just because you realise how precious life is and it puts it all in perspective, the idea of not being around to see your children grow up.

“But you know, from some of my earliest memories I remember my mother and father taking us to charities and organisations and showing us, you know, what... what goes on.

“And I think it’s seeing... such a broad spectrum of life, it’s really important from a young age, to give you a bit of perspective to go you know, you don’t just live in a palace, it’s very important you get out and you see what goes on in the real world.”

Prince Harry told Ant and Dec that gaffes were usually viewed as disasters by charities or other groups hosting engagements, but royal visitors secretly prefer it when things do not go to plan — particularly the Duke of Edinburgh. He said: “Everywhere we go, everything is sort of rehearsed so much, that it’s always bang on correct, perfect. But we all, no more so than our grandfather, love it when things go wrong.

“And you always turn round and say, ‘Don’t worry, it’ll probably go wrong’ and then it does go wrong and they’re sort of crying; I say ‘Don’t worry about it, it’s actually [good], now I will remember it even more’.”

While at Eton, the princes would receive letters from their father but his infamous “black spider” handwriting was so bad that they would have to read each other’s for a second opinion in case they were being told off without realising it.

Prince Harry said: “At school, we... said ‘Erm, I think I know what it says, can you read it to me?’ And it was just drivel.”

His brother also revealed they would read the letters to each other “just in case it was a bollocking we didn’t know about”.

The Duke added: “As it gets later in the evening, it’s about 12 o’clock when he’s writing letters, we can tell instantly. When he’s falling asleep you get these long sort of As that disappear off the page.”

The brothers enjoy being neighbours at Kensington Palace: Harry said he likes hearing his nephew Prince George playing on a toy tractor outside, while William said Harry “scrounges all food off us and things like that”.

Ant and Dec spent a year shadowing them to find out about the work of the Prince’s Trust, a £70 million (Dh378.8 million) per year charity that has helped 825,000 disadvantaged and vulnerable young people move into education or work by giving them loans and mentoring.

A rare on-camera chat with the Duchess of Cornwall sees her admit to being “really proud” of her husband’s “incredible” achievement in setting up the Trust in 1976. The Prince of Wales told Ant and Dec he hopes one of his sons “might take an interest in [the Prince’s Trust] because I’m probably getting past my sell-by date now”.