"Usually I just fling a tracksuit on," admits Stormzy, real name Michael Omari, wrestling his long arms from a velvet dinner jacket to better roll a cigarette. "But it's good to step out of my comfort zone." In fairness, the 23-year-old's "comfort zone" seems a wise place to lay base right now. Despite pressure to release his long-awaited, oft-delayed debut album and sign to a label, the UK's most talked-about rapper is determined to do things on his own terms, in his own time — and the results speak for themselves.

this image is not availablepinterest
Bear Grylls//Digital Spy
Black wool tuxedo jacket, £1,150; black silk bow tie, £85; white cotton shirt, £190; black wool tuxedo trousers, £350; black silk cummerbund, £370, all by Emporio Armani

With "Shut Up", Stormzy is the only unsigned UK artist to ever score a top 10 hit. The video (watched over 41m times on YouTube ), was shot on the fly in a park next to his childhood home in south London. In 2015, he was the Mobos best male artist and recently Manchester United celebrated its record-breaking £89.3m signing of Paul Pogba by enlisting Stormzy to rap and dance alongside the French midfielder in a music video. Omari is considered the country's next legitimate transatlantic hope: good looking — all 6ft 5in of him — charismatic and, above all, credible.

"That's the beauty of my story: the fact that it's backwards," Stormzy says. "I'm the total opposite of where I should be. I'm releasing my debut album after touring the world! Everyone around my pedestal is at least two albums and 10 years deep. I'm a prominent member of my scene."

The scene he refers to is grime, a genre that's long simmered under the mainstream since emerging from east London housing estates in the early Noughties. In the past three years, it's become the most exciting British music phenomenon in a generation. At a time when most of our creative achievers are white and privately educated, grime has muscled young, disadvantaged minority voices to the forefront of the cultural conversation. "I feel like the whole country has noticed they've missed something," Stormzy grins. "They're thinking: 'How could this have been going on all this time?' It'll never be ignored again."

this image is not availablepinterest
Bear Grylls//Digital Spy
Black wool-mohair evening suit, £945; navy cashmere crew-neck sweater, £425; white silk pocket square, £55, all by Richard James. Black leather derbys, £280, by Tod\'s

But the genre has suffered false dawns before. Half a decade ago, in an impatient bid for mainstream success, grime artists (such as Tinchy Stryder and Chipmunk) began to collaborate with chart-topping pop stars. The scene appeared in danger of losing its cool, and Stormzy is determined not to let that mentality take over again.

"Back then, record companies said: 'Do this, otherwise you can't have a career.' But radio and record labels don't have that power no more. I freestyle and put it on iTunes, it goes top 10 and the radio has to play it. People hold the power now. I'm just going to keep on doing what I was doing before anyone knew my name."

this image is not availablepinterest
Bear Grylls//Digital Spy
Navy wool coat, £1,200; navy merino wool long-sleeved T-shirt, £90; navy moleskin trousers, £350, all by Private White VC.Black suede desert boots, £165, by Russell & Bromley

Can grime's very Britishness translate overseas? US rappers have transformed tales of their beleaguered inner cities into global anthems chanted in the far muddy fields of Glastonbury, but will Stormzy really be able to make his hometown of Croydon matter to a rap fan in Chicago?

"I will die before I change my sound to suit an American audience. You won't ever hear Kanye West or Kendrick Lamar change their beats to appeal to the British," says Stormzy, fixing a firm, unwavering gaze. "It's all about telling the world: 'This is it. Listen to it and get used to it, because we're not changing.' One day, hopefully, my voice, my accent and my decorum will be universal. Because if I'm not me, then who the fuck am I?"

That's true whether he's wearing a tracksuit or a tux.

this image is not availablepinterest
Bear Grylls//Digital Spy
Black wool-twill-silk evening coat, £1,330; white piqué cotton shirt, £180; charcoal wool twill trousers, £255, all by Pal Zileri. Black satin bow tie, £95; black satin cummerbund, £115, both by Drake\'s
this image is not availablepinterest
Bear Grylls//Digital Spy
Black velvet dinner jacket, £275; white cotton shirt, £75; black wool-mohair trousers, £135, all by Jaeger. Maroon velvet bow tie, £65, by Turnbull & Asser
this image is not availablepinterest
Bear Grylls//Digital Spy
Black cotton-piqué double-breasted blazer, £1,200; navy cashmere roll-neck, £500, both by Dolce & Gabbana
this image is not availablepinterest
Bear Grylls//Digital Spy
Black/navy wool bomber jacket, £650; light grey merino-silk sweater, £230; black textured wool-cotton trousers, £175, all by Paul Smith

Fashion: Mark McMahon