Speech Debelle: 'My mistake was to think I'm a celebrity. But I'm not like Take That – I'm an artist'

Since unexpectedly winning this year's Mercury prize, the rapper Speech Debelle has had to contend with high expectations, low album sales and the boos of Take That fans. And still, she says, this has been the easiest year of her life so far...

It all seems like such a long time ago now. It was May 2009, and Speech Debelle – real name Corynne Elliott – finally got to release her debut album. Two years in the making, Speech Therapy was a low-key but beguiling mix of hip-hop, jazz and folk that was sometimes naïve, sometimes meandering, but no less appealing for that. Its lead single, "Spinnin'", was a particularly sweet confection, a kind of musical peace sign that would have sounded wonderful on daytime radio had daytime radio schedulers chosen to playlist it. Curiously, they never did. That said, Elliott remained optimistic.

"I was expecting 50,000 sales, the Mercury prize, a Mobo [Music of Black Origin] and a Brit Award," she says seven months later over a limp croque-monsieur in a greasy spoon in Crystal Palace, south London. She speaks so plainly here that you know she isn't joking. "Won the Mercury, never even got a Mobo nomination, and – wait a minute – have the Brits come and gone yet?" Next February, I tell her. "Something to look forward to, then."

Debelle appears remarkably unfazed for someone who has endured one of the more roller-coaster rides in music this year. She has a bright, smiling face offset by wary eyes that hover beneath a pair of French Connection glasses. When I bring up what she hasn't yet mentioned – those hoped-for 50,000 sales – her eyes promptly glaze over. Despite the fanfare that accompanied the Mercury award (below left), her album somehow tanked, stuttering out at the 10,000 mark.

"But probably double that in digital sales," she adds, bristling. "People ask me all the time if I'm disappointed by that, but why would I be? I got my music out there; that's the important thing. Then they ask me about all the hurdles I've gone through this year. What hurdles? Hurdles is when you have to take the Tube to work every morning, then sit in an office all day. This year?" she says, picking up her sandwich. "This year's been the easiest of my life."

And yet, as it draws to a close, it is no longer even clear whether she remains on her label, Big Dada, any more. It was recently announced that she ditched them. "Am I still signed to them?" she will muse later, looking out of the window. "I don't know if I care any more, to be honest...

Corynne Elliott, now 26, had wanted to become a singer ever since she fell under the spell of Michael Jackson's single "Human Nature". She was drawn to the song, she says, because of its overriding sentiment, "and I do love a genuine sentiment". She was 13 years old, and when she soon after discovered that – to her ears at least – she couldn't quite carry a tune, she turned to rap instead and spent the next several years writing rhymes, then setting them to beats.

She grew up in Gipsy Hill, a stone's throw from the café in which we meet on this wet December day. Her mother worked for the local housing benefits office, and she never really found out what her father did, as he left the family home when she was just six. She has eight step brothers and sisters, and family life was forever eventful. At the age of 19, after continual arguments with her mother – the precise nature of which she would rather not go into publicly – she left home.

"It's been reported that I was homeless, but that's not strictly true," she says, although it is true that she spent the next four years in and out of hostels. "I stayed on friends' couches, too, but the hostels, yeah, they weren't really a healthy environment. Stay in a hostel for any period of '

time and you realise just how dangerous alcohol is to so many people. Much more dangerous than cocaine, crack, all that stuff." She vaguely references this time on the album track "Better Days": "I've been spending quite some time thinking about my life/ I've been acting loose, but not in every way/ But enough ways to put me in the wrong place."

"How did I spend my days?" she asks. "I started studying counselling, but that didn't last. Mostly I just drove places with my friends. Where to? Nottingham... anywhere, really. Nothing else to do." Eventually, she craved an escape back to a healthier, more proactive lifestyle. She tells me that things were getting bad at the hostel, and that she wanted to get away from the "big boys". "I was worried I would come under their influence. A couple of friends had gone to jail, and I didn't want to follow them." What had they done? She looks down. "Nothing violent. Just trying to make some money, you know?"

Whenever she made some money, she spent it in a local studio, recording demos. In 2005, one fell into the hands of Will Ashon, the founder of Big Dada records. Impressed, he offered her a deal.

"I looked at the contract and it was shit, so I said no," she says. But two years later, with no better deal forthcoming, she rang him to ask whether the offer was still open. It was. She spent the next two years recording her album on a rather restricting budget, while holding down a day job as a researcher in an advertising company. She only quit when the album was released in May, and suddenly found herself on the road to promote it. Having never performed live before, she learnt a valuable lesson about herself: she suffered terribly from stage fright. "But then I found myself playing places like Glastonbury," she says. "I had no choice but to lose the stage fright quick." How? "Well, a few drinks helped..."

By August, Speech Therapy had achieved the improbable: a Mercury nomination. This was an unexpected boon for what was ostensibly a small record on a small independent label, although, as the music journalist and Mercury judge Jude Rogers points out, "The Mercury shortlist always is a great opportunity to introduce people to records they otherwise wouldn't have heard." Debelle's album, Rogers says, "had such a fresh voice; it was open and candid and very British. I loved it from the get-go, and I was so pleased when it won."

To the outsider, the album stood no chance against the more obvious frontrunners Kasabian and the 2009 indie darlings Florence and the Machine. The woman herself, of course, was far more confident. "Ever since Ms Dynamite won it [in 2002], I knew I could win it myself," she asserts. "Ms Dynamite looks like me; I had cousins that could have been her. You know, we came from the same kind of background, similar kind of music, and I just knew that if she could do it, I could too. And I did."

It certainly brought some welcome limelight to a record that had, to that point, sold only 3,000 copies. The broadsheet press embraced her, but then rather confusingly pitched her against last year's winners, Elbow, who went on to sell more than 300,000 copies of their winning effort, The Seldom Seen Kid. In stark contrast, Speech Therapy managed just 7,000 further physical sales, failing even to crack the top 40. If, as she has suggested since, fans simply couldn't find the record in HMV because the record company were not able to ship them fast enough, then few people chose to attend her live performances either. Within a week of the prize, 40 people turned up to her gig in Sheffield.

"That's true, Sheffield was pretty bad," she concedes, "but when I played London after that, it was to 800. The press never mentioned that, though, which gave me a good idea of just how they work. Earlier in the year, I was the greatest thing since sliced bread; now I'd won an award, they wanted to take me down a peg or two."

Did winning the Mercury bring with it unfair expectations that a young artist of her calibre simply couldn't match? Jude Rogers hopes not, but says, "It is true I've felt nervous that winning may not have been the best thing for her, if only because of all that foisted expectation. We tend to judge success on sales these days, which is a shame. I personally never thought Speech Therapy would be a big seller, but rather a cult favourite. It's a small, intimate, lovely, fresh and inventive record, and it really does deserve an audience."

Radio never thought so. In an era in which personality is as important as musical content, it perhaps shouldn't come as much of a surprise that Debelle was never going to compete with the likes of Lady Gaga for heavy rotation. But, just as Radio 1 ignored her, so too, more inexplicably perhaps, did urban stations. "Ah, but let's say that you are a black artist who doesn't necessarily conform to type," Debelle says. "You like Kings of Leon, and you're not particularly a fan of Jay-Z. In other words, you don't fit in, and so you get overlooked. It's why I didn't get a Mobo nomination, either."

And as to building a mainstream audience through word of mouth, it might be fair to suggest that Speech Debelle didn't exactly help her own cause. Last month, for example, she was booked to appear at a celebrity-studded event in honour of the pop group Take That. Against her better judgement, she agreed to turn up, and was then asked to take the stage to sing a version of the band's single "Pray", while Take That watched on from the wings alongside celebrities such as Lily Allen and Kate Moss. Debelle's stage fright returned with a vengeance. To prepare herself before going on, she downed a glass of wine. Then she finished the bottle. Then she belatedly remembered that she didn't know the words.

"I didn't realise it until the following day when I saw footage of it," she says, "but I was up there slurring. I embarrassed myself. I was a drunken fool. And then I started insulting everybody..." The audience booed her as she stalked off, and the event's compere, Gavin & Stacey's James Corden, pronounced her performance "shit". Deciding this was fighting talk, Debelle clambered back up on stage for a confrontation. "And I shouldn't have."

She says now that she learnt a valuable lesson from the experience: not just to avoid drinking before a show, but also to learn to say no to such offers, and not allow herself to be swayed by the advice of others. "It made me think carefully about the company I keep," she says. "I am an established artist, a Mercury-winning artist. I don't need to do things like that alongside those kind of celebrities. My mistake was believing that I was like them. I'm not." She then lets slip an entirely uncorroborated and potentially libellous allegation against Take That, which suggests that perhaps she hasn't learnt from the experience after all.

In the same week as the Take That performance, things were to take a further turn for the worse. In an interview with BBC 6 Music, Debelle appeared to lay the blame for her poor album sales directly with her record company. The next day, it was reported that she had parted ways with them. She laughs pithily. "I rocked the boat again, didn't I? But it all got taken out of context. So I started an argument with my label; so what? I'm always arguing with them. It's nothing new. Ask them."

So is she still signed with them, or not? When I contact Big Dada direct, they refuse to comment. "Why would they not want to continue their relationship with me?" she asks. "I'm probably the most successful artist they've had." Presumably she isn't easy to work with? "Ha! Probably not, no. But if you'd had a record label for 10 years, and then you got to sign me – well, what would you want to let me go for?" But then she adds, as a rather confusing coda: "Anyway, I've got more options now than I did a year ago, so we'll see, shall we?"

And we leave it like that, deliberately vague, the woman far too bullish to ever admit to having burnt perhaps one bridge too many.

Speech Debelle's 'Speech Therapy' is out now on Big Dada. A new album is planned for next year