Singer Mutya Buena: Don't call me babe

"I've already explained to people: I will not hold back my mouth for no one," announces Mutya Buena, with the sort of no-nonsense defiance you'd expect from a girl who sports a diamond stud above her lip. "At the end of the day, I've kept quiet for the past two years, and I've not said nothing. I could have if I wanted to, but I don't believe in blagging."

Buena is determined to set the record straight - but she's endearingly good-humoured about it all. Yes, she'll tell it like it is, but no, she's not a bitch. She doesn't hate new babe Amelle Berrabah ("I have never once said that she is a clone because, one, she doesn't sound like me, and, two, she doesn't look like me") and certainly didn't use her baby daughter, Tahlia, as an excuse to leave the band. "Obviously, I'm going to choose my daughter over my career," she reasons. "My career means a lot to me, but it doesn't mean that much."

Things have always seemed tumultuous with the Sugas ever since original member Siobhan Donaghy bid farewell in 2001 amid claims that she was being bullied. Even when Heidi Range joined the crew, Buena admits she didn't initially warm to her. But now that the 22-year-old is on the other side, she can see things a lot more clearly. "Now that I'm not with the Sugababes, I realise that we are very different people and I think it actually takes for you to move on with your life to realise certain things. We are totally different people. I can see where we would clash."

Something else that "things" have taken their toll on is her friendship with Keisha Buchanan, whom she has known since primary school. "I think mixing friends and business isn't the key," says Buena philosophically. "You fall apart or you become stronger as friends. And Keisha knows, as I knew, we drifted apart. Most of the bickering [in the group] was probably me and Keisha. That's how it is: females - I can't take much of them. That's why I have a lot more male friends, because females are very bitchy, and I can't do bitchy."

Reinventing herself as a solo artist has understandably been a blessing. Although she planned to go into producing and songwriting after she left the group in 2005, Buena was offered a deal that, she says, she'd be silly to turn down. Sitting in an office at her label's headquarters, she projects a mixture of excitement and nervousness when she discusses her turn of fortunes. "Obviously, I was gonna take the opportunity," she smiles. "I was gonna say 'No', but I thought, 'You know what? I've got a mortgage and I've got a child. Bills have got to be paid, and I have to do what I have to do.'" The result is the R&B/pop-fuelled Real Girl, an album that reveals the Buena we'd always imagined her to be: deep, soulful, sincere and feisty.

Buena is the daughter of an Irish father and a Filipino mother, has five brothers and three sisters and hails from north-west London. As a teenager, she became interested in music and was hoping to develop as a solo artist. She soon started recording music with Donaghy. Buena was keen on getting Buchanan involved and later invited her down to the studio. The rest is history. But being in the band occasionally took its toll. "I wish I'd stayed in school and finished off properly, done the whole teenage thing," Buena admits. "I got kicked out of school when I was in Year Nine because we were working so hard that I was always late for school or I never went to school because I was so tired. I was out of school for about a year and a half."

Would she have left the Sugababes sooner rather than later? She blinks, and takes a moment to deliberate. "When I was younger, I most probably tried to get out of the Sugababes just for the simple fact that I couldn't take being pushed about and moved about, and missing your family. I saw the girls more than I ever saw my family and I've grown up in a very tight family. And to be away from them and to be with other people, it's like having to change home again. It was too much for me."

Having her daughter in 2005 was the tipping point, after Buena suffered post-natal depression. "Everyone [around me] was trying to say, 'Oh, well, everything's going to be fine.' And there's me trying to explain to someone, 'No, it's not going to be fine,' because I'm not feeling right within myself... You just don't know what it feels like until you're actually in it."

Now, things are looking up. Already endorsed by George Michael, with whom she duetted last year, she's giving this solo thing a go, and is just content that she finally has the last say in her life. But she admits: "At the end of the day, I also know if it doesn't work out, I tried. It wasn't something I was gonna carry on doing anyway. But if it goes really well, then obviously, you know, hopefully I'll enjoy it."

'Real Girl' is released on 4 June by Universal