'My muscle condition won't stop me playing Glastonbury'

Last week, he was sitting his GCSEs. This week, he'll make his debut at Glastonbury.

Eli Crossley, who's just 16, will be one of the youngest performers ever to play the festival when he takes to the stage with his band, Askew.

And he's doing so in spite of the muscle wasting disease that's confined him to a wheelchair for the last year.

If the magnitude of the event is playing on his mind, it doesn't show.

"I've got three exams left, and then we've got this small concert," he laughs over the phone from his home in London, a week before the festival.

Eli has Duchenne muscular dystrophy, a progressive and life-limiting condition that gradually makes his muscles become weaker.

His big break came about almost by accident when, earlier this year, he appeared on BBC Breakfast to discuss his condition.

The teenager was showing off a new piece of technology called the Smart Suit that, it is hoped, will help him continue to move his upper body when he grows older.

Asked how comfortable the device was to wear, he replied: "It's very comfortable and I hope it will help me in fulfilling my dream of playing Glastonbury."

His mum, Emily Reuben, joins us on the call. "I don't think anyone thought you were going to mention Glastonbury," she laughs.

"It just sort of came out and the whole thing went viral. I was impressed. You put your dreams out there."

It didn't take long for social media to take up the cause, petitioning festival organiser Emily Eavis to give Eli and his band a slot.

After an initial flurry of activity, however, the requests died down. Then, a parent at Eli's school saw Askew performing in an end-of-term talent show.

That parent just happened to be Jon Turner of Island Records. The following morning, calls were placed to Eavis and her husband Nick Dewey, and the cogs turned.

"They saw the video of Eli and said, 'Yes, we'd absolutely love to have him'," Ms Reuben recalls.

That evening she posted a cryptic message on WhatsApp to the group's parents: "Major news incoming." Soon afterwards, Eli started making calls to his bandmates Alfie, 15, and Freddie, Jay and Will, all 16.

"I didn't believe him at all," says Will, who plays guitar. "I thought it was a little joke."

"Will is fairly new to the band and he said, 'But I've never played a gig before'," Eli recalls.

"And I was like, 'Yeah, well you're playing Glastonbury now, mate.'"

"We've never played anything this big," says second guitarist Jay, admitting to a degree of nervousness.

"We've only really played in front of our parents and in small bars and stuff. We never thought we'd be here. "

Asked how he feels about the show, even Eli's bravado falters temporarily.

"I'm terrified about it, but really excited at the same time."

But the band have already got the support of one famous fan, actor Eddie Marsan, who implored festivalgoers to catch their set.

"Eli is not only a remarkable young man, he's a phenomenal musician," he wrote on Twitter.

"I saw his band Askew play in Paris and their set was incredible. They're going to blow Glastonbury away."

The group will play at 17:30 BST on Friday on the small and secretive Rabbit Hole stage - an underground venue where punters have to answer a riddle before they can enter.

Their half-hour set will mix originals like Rosemary and Last with covers of Queen's Crazy Little Thing Called Love and Supersonic by Oasis - "a few crowd pleasers to make sure everybody stays put", as Eli puts it - before they're set free for the rest of the weekend.

Eli is determined to see Royal Blood on the Pyramid Stage, while his mum has made it clear she'll be watching Sir Elton John on Sunday night.

After that, she will go back to the day job of running Duchenne UK, the charity she set up after Eli was diagnosed with muscular dystrophy 13 years ago. At the time, she was told her three-year-old might not live to see 20.

Along with co-founder Alex Johnson, she has raised more than £17m, which has been used to fund clinical trials across the UK, as well as partially funding 34 posts for doctors and nurses, creating guidelines for care for Duchenne patients and research into how technology can help them. Both women received OBEs from King Charles last weekend.

It was part of their research that led to Eli's initial appearance on BBC Breakfast, discussing the motor-assisted suit that will help him continue playing guitar when his arm muscles begin to waste away.

She says the suit will mean "being able to brush your teeth, give your mum a hug [or] put your arm up in class. All the little things that are actually the really big things".

With help from the Postcode Lottery, they have 10 prototypes in development, and hope to make the suit widely available within three years - helping not just children with muscular dystrophy, but other conditions including spinal injuries.

"She's an inspiration not just to me, but to many people around the world," says Eli.

Clearly, his mum feels the same way about her son.

"I just can't believe it. We never in our wildest dreams thought that dream of his would ever come true," she says.

"These boys work really hard and they rehearse a lot. I know they're going to smash it."