No, really. We're serious...

'I want you all to repeat after me..." Justin Hawkins, bare-chested and squinting into in the scorching midsummer sun, has 120,000 people in the palm of his hand. His onstage banter is well known to long-term fans. Once, back in the day, it might have been a shrill instruction to "Suck my cock!", but, in the family-friendly context of a recent slot at Knebworth, opening up for Robbie Williams, it's more likely to be the familiar "Gimme a D! Gimme an... Arkness!"

Hawkins can be forgiven for a touch of the I-told-you-sos. This is, after all, one of the least likely, and most life-affirming success stories of recent years.

Outside the row of temporary cabins backstage, it's like a scene from Stella Street. There's Jack Osbourne, deodorising his armpits in the gents. There's his sister Kelly, zebedeeing around in preparation for her own set. There's the little guy from Ash, brushing past Moby. There are the proud parents, Mr and Mrs Hawkins, carrying a copy of the Lowestoft Gazette, complete with "Before They Were Famous" cover story on their sons. And there's Robbie Williams himself, stepping out of his RW helicopter too late to actually see The Darkness, but throwing an arm around Justin and mendaciously saying "You guys were great."

Back in the spring of 2001, Valerie Gayrimond, promoter of The Fan Club at The Verge, urged me to check out this new band with the dodgy, gothic-sounding name. I reluctantly attended, but found myself utterly enraptured by what I excitedly reported to Independent On Sunday readers - in the band's first ever live review - as being "a histrionic, high camp heavy metal band, best described as a gay AC/DC fronted by a young Freddie Mercury ... hugely entertaining, regardless of their exact location on the irony-seriousness scale."

In 2003, suddenly and gratifyingly, the world has finally woken up to The Darkness. Throughout a summer in which they have tirelessly played every festival on the calendar and supported the likes of Def Leppard, Deep Purple, Meat Loaf, Metallica, Robbie and, shortly, The Rolling Stones, the shameless effervescence of the band's showmanship has picked up thousands of new fans, causing an irresistible snowball effect. After years of mass-marketed miserablism and fake angst, The Darkness aren't simply the band who have put a smile back on the face of music - they might just be the band who save rock'n'roll.

The four members of this rock phenomenon are kicking back in the cool, dark interior of their dressing room. There's Justin Hawkins, the flamboyant, tattooed singer, whose super-dry sense of humour leaves you permanently unsure whether he's mocking you, himself, or both. He's the kind of guy who'll ask for an orange juice, and just as you're on your way to the bar, add "Oh, can I have a bit of vodka in it?" There's Dan Hawkins, his younger, pretty boy brother, who is perhaps more serious, certainly more introverted, and who owns eight identical Thin Lizzy T-shirts.

There's Frankie Poullain, the enigmatic, Bronson-moustached bassist from Tayside who has his own growing fan cult. And there's Ed Graham, the drummer whose mood swings gave the band their name ("Uh-oh, Ed's got the darkness again...") He doesn't say much, but he shows me a blister on his thumb that looks like the bowl of a live volcano.

They've just taken Knebworth by storm for the third day running, as though they were to the manor born. Anyone who witnessed one of those early pub gigs instantly knew that The Darkness merited - "demanded" - a bigger arena. It was just a question of getting there. The thing which made them so anomalous was their lack of modesty, their insistence of pulling stadium moves in pub rock venues.

"Stadium rock is only called stadium rock," Justin muses, "because that is the ideal location for it. Pub rock has different connotations. We were only playing pubs because we had to. We were saying 'This is what we do. Right now we're doing it here, but one day we're gonna be doing it there."

The Darkness's attention to stagecraft - from Justin's sequinned catsuits ("You don't find a good catsuit. It finds you"), to the choreographed high fives, to the piggyback walkabouts through the crowd, to their touching habit of setting up a buffet on a trestle table at early gigs (they were once forced to cancel a show after Dan sliced his finger while chopping cheese into cubes) - meant that some dull souls marked them down as a novelty act of little musical substance.

"We insist on everyone having a good time. But we spent far more time perfecting the songs than we did worrying about what to wear," Justin insists. "The Mercury nomination is an amusing indication that the album is the cake, and everything else is the icing."

Permission To Land is a brief ten-song salvo which was completed in a two-week burst, because, says Justin, "my favourite albums are recorded as quickly as possible, so you get a chronological indication of where the band were at, at that particular moment."

It wasn't lack of material which kept it short: the band started with 48 songs, but never wrote anything down on the principle that, if it wasn't catchy enough for them to remember it the next day, it wasn't meant to be.

Justin takes up the thread. "You know that terrible cliché, have as much fun as possible in as short a time? There's a bit of that about us. Because if we were hit by a bus tomorrow, that would be our only document."

Having conquered their homeland, the next stop, logically, will be America, where The Darkness's old school party rock should go down a storm.

"The whole thing that's held us back here," reckons Frankie, "has been 'Are they taking the piss?' but that isn't an issue there. We'll be judged on the merits of our performance."

"There's New York and LA," says Dan, "the cool parts where they're receptive to British bands. But there's also the bit in between, which is vast, and highly populated. And that's where we're at. We have no concept of being cool. If anything, we fight it. And those people will get off on it."

"For me," Justin agrees, "New York is... Luxembourg. And LA is Malaysia. And Middle America... that is America."

The sudden upward curve of The Darkness's fortunes must make it difficult to take stock of how drastically their fortunes have altered. "It's the wind of change," says Dan, starting to whistle, and prompting a memory from his brother.

"I was taking a holiday in Crete and a guy thought he recognised me. He said 'Are you the guy from The Scorpions?' "

"There's never any time to sit around sucking each other's cocks," Frankie says.

"I dunno," Justin frowns, "...only yesterday we were doing it all the time."

The Darkness support The Rolling Stones at Wembley Arena on 15 September and their national tour starts at Keele University on 4 October. Their album, 'Permission To Land', is out now on Must Destroy, and a new single 'I Believe In A Thing Called Love', is out on 22 September. For further information, see www.thedarknessrock.co.uk