Speaking later to an audience of charity partners and young people, Harry claimed the country could spend hundreds of millions of pounds on the problems caused by a lack of sport in young people’s lives or “you rip up all those cheques and start at the beginning to prevent it from happening in the first place”.

“I think this campaign will prove that, if we invest early on in young people, in the right areas with stuff that already exists – we’re not trying to create or invent anything new – this works and this is going to be full circle back to how we’ve always believed that change can happen.”

He also told his audience, at the Black Prince Trust’s Community Sports Hub: “We have a responsibility in this campaign to ensure places that are being shut down are not being shut down and that people from all walks of society and every corner of this country are actually given the opportunity to shine, to flourish.

“This is about community, this is about providing opportunity to young people all over the place to actually be part of something, something they might not be getting at home, within their own community.”

Boxer Ms Adams told ITV News funding in sport is so important because it could be difference between finding a champion and losing out on one,

Harry with boxers Anthony Joshua and Nicola Adams (front centre) at the launch in Kennington, south London.

She said: “The champions could be right there – that person who couldn’t afford those boxing gloves to be able to take up the sport.

“That could’ve been an Olympic gold medallist right there and they’ve missed their chance.”

When Harry first walked into the boxing gym, he watched teenagers sparring under the watchful eye of Joshua, who suffered a shock defeat to Andy Ruiz Jr in New York earlier this month, losing his IBF, WBO and WBA world titles.

The duke, who has boxed in the past, said the sport allowed participants to “get out the anger and aggression which everybody has”, and Joshua added: “All you need is a T-shirt and some gloves.”

Harry later climbed into the ring to meet Adams, who is hoping to set up a world title fight before the end of the year.

After chatting to the duke, she said: “Boxing’s done the world for me – I’ve travelled everywhere, I’ve received an MBE and an OBE, I’ve become a double Olympic champion, it’s changed my life.

“Just because I’ve had the opportunity to be able to participate, that’s why I’m quite excited by Made By Sport, it’s a really nice charity, it’s going to do the world of good.”

Harry also chatted to Gizmo Chu, 29, a personal trainer and a boxing coach with a charity using the sport to help children avoid the risk of falling into gangs.

He described how he was expelled from school at 15 and a year later was in Feltham Young Offenders’ Institution but had discovered boxing by the time he was 18 – a life-changing moment.

Speaking after meeting Harry, he said: “We all want to be part of something and if you’re not one of the brightest kids in school you’re left with the naughty kids and I didn’t fit in too well.”

Prince Harry and Anthony Joshua joined the launch of an ambitious project to raise £40 million to boost the work of charities delivering sport in disadvantaged communities.

He added: “I’m not a world champion, or had a hundred bouts or become a professional, but what boxing has done for me has helped me through the past 12 years – without boxing I’d be a very different character to what I am today.”

Made By Sport will be delivered in collaboration with the Sport For Development Coalition of more than 60 charitable organisations and will be chaired by former Sainsbury’s chief executive Justin King.