Something curious comes over the Duke Spirit's Liela Moss when she's on stage. Standing up there in front of a crowd, she's the lightning rod along which her bandmates' stormy racket crackles. Glaring through a peroxide fringe, she hangs from the microphone with one hand and thwacks a tambourine against her hip with the other. She fizzes with lust and menace and faintly disconcerting charisma. When she is at her most commanding, it feels like there is no more magnetic frontwoman in the country.
Today, though, it's as if a different person inhabits Moss's body. Hungover and hesitant, she toys with a cranberry juice in a pub basement, beside guitarists Luke Ford and Dan Higgins. She says that when she is performing, she gets her confidence from the people around her. Without them she'd be lost: "I'm not a solo artist with a band of good little fellers I've hired in."
Reluctantly or not, she is becoming an iconic figure. When I ask about her appearance in NME's daft but compelling Cool List last year, she brushes it off: "Oh. I didn't really think about that." Then Higgins goads her and she gives the quick laugh of someone who's been caught out. "Well all right," she concedes guiltily. "I was flattered."
The Duke Spirit's debut album, Cuts Across the Land, has been a long time coming, but if you've turned up early to a gig over the past two years it's possible you've already heard the songs - the band have warmed up for the Vines, Razorlight, Kasabian, Mark Lanegan, the Yeah Yeah Yeahs, the Rapture, Mercury Rev and British Sea Power. Their friendship with the latter makes perfect sense. Like BSP, they draw unabashedly on the rock'n'roll canon - in their case, the scowling, leathery tradition represented by the Stooges, the Velvet Underground and the Jesus and Mary Chain - while finding more oblique inspiration in English arcana.
But where British Sea Power's England is one of birdwatching, civil defence and windswept crags, the Duke Spirit tap into something much more primal. The familiar rollcall of influences on their website (Keith Richards, Bill Hicks, Midnight Cowboy and so on) doesn't tell the whole story. Listen to Cuts Across the Land and you can discern the witchy sexuality of PJ Harvey's pagan blues, a flicker of The Wicker Man, a suggestion of darkness encroaching on woods and fields. Their record sleeves, designed by Higgins, are based on 17th-century woodcuts populated by demonic pugilists and leering skeletons. At the same time as most new bands are busy acting like it's 1982, the Duke Spirit offer an intriguing whiff of 1682.
Higgins spent his formative years in rural Dorset. "I used to put White Light/White Heat by the Velvet Underground on my Walkman and walk around the hill forts and glades, and somewhere in all of that something clicked and made sense." Employees of the Dorset tourist board take note.
Moss, an only child whose parents separated before she was old enough to remember them together, grew up with her mother in Gloucestershire and visited her father in London. "I remember it feeling so serious. All of my experiences were split down the middle into good/bad, guilty/not guilty, living with your dad/living with your mum. Just a lack of harmony."
She remembers wandering off on her own to explore the countryside, and obsessively listening to a vinyl recording of TS Eliot's Four Quartets read by Alec Guinness, undeterred by the fact that she could make neither head nor tail of it. It sounds like she must have been a serious child but she's not so sure. "I think I harboured problems and became quite thoughtful but really that would only have been a part-time thing because I was a little fat spotty girl who did funny accents."
Her dark, allusive lyrics weave the imagery of fairytale and myth into an enthralling private language. "Fairytales give you a really clear symbolic language. It's almost like I'm tapping into something I would ordinarily ignore. I'm speaking to myself really. Perhaps that's why I can do it. If I felt like I was writing for an audience and telling them what was going on in my head I'd probably just stop."
It's a wonder she ever got started. She first met Ford and bassist Toby Butler several years ago; all three are closer to 30 than 20. She was studying in Cheltenham, where Ford and Butler were attending art college. They talked about forming a band, but Moss took some persuading. "I secretly wanted to sing but I felt like admitting I wanted to be in a band was such a cliche. I was really uptight about it. Luke was constantly saying, You should sing. And I'd get really arsey about it, wouldn't I?"
"Mmm," Ford agrees meaningfully.
Their rapport makes sense when it turns out they were in a relationship for several years. "It's something that could have been really difficult," says Ford, "but that hasn't happened." Along with Butler, they moved to London, where they spent the next few years "kicking around", putting on art shows and playing in a band called Solomon, named after Toni Morrison's novel Song of Solomon. Higgins remembers being a frustrated onlooker: "I used to come and see you and think: 'Come on, be a bit bigger, a bit louder, a bit more.'"
"It was a flawed blueprint for what might come next," says Moss. "We scrapped it all two-and-a-half years ago and said: 'Right we want to do this for real - no insecurity, no fearfulness.' I felt something snap inside me one night and I swear I woke myself up with it: I'm not going to pussyfoot around anymore, I'm not going to be embarrassed by what I write about."
Joined by Higgins and drummer Olly Betts, the former Solomonites agonised over a name, settling on a random phrase taken from an uncorrected proof they found in the office of their producer, former Cocteau Twin Simon Raymonde. Moss doesn't even remember what the book was about. "For us the duke spirit is a sense of ennoblement for everyone. We like to have an inclusive atmosphere. I'd hate to be so cool and so much of a gang that the audience isn't a part of it."
So it seems. While most new bands fall over themselves to construct a carapace of cool, the Duke Spirit are refreshingly keen to dismantle theirs. "We can sound really serious and thoughtful and literary but we're always so fucking undignified on tour," sighs Moss, to murmurs of agreement from Ford and Higgins. "I'm so unsophisticated." She lowers her head, retreating behind her fringe like a teenager.
"We did this show in Spain and we'd hopefully created this impression for the audience," says Ford. "Then we got really drunk, went downstairs to this party and ... unravelled."
"There was a moment like: 'Oh shit there's some kids that just saw us,'" says Moss. "They look like French beat-poets and there's us with our arses falling out of our jeans going, 'Come on!'" She peers up from her drink, a smile creeping across her face. "It's high contrast."
· Cuts Across the Land is out on Monday on Loog. The Duke Spirit's national tour starts next Thursday.