Marina & the Diamonds shines on

If people could talk their way to stardom, Marina Diamandis would already be a household name. Almost giddily ambitious, she named her fans the Diamonds when she didn't even have any fans. When she put out her first DIY single in 2007, she would turn up at interviews, full of laughter, outlining plans for world domination, outlandish costumes, extravagant live sets, bizarre merchandise and the unshakeable conviction that she would be headlining the American MTV awards "in three years".

Which would bring her up to 2010. Where, back in the real world, Marina & the Diamonds (as she styles herself) has sold 150,000 copies of her top-five debut album (The Family Jewels), scored three top-40 singles and is about to embark on another sold-out British tour — but is still awaiting that invitation from MTV.

"I don't feel like a success, and that is a kind of success in itself," declares the 24 year-old Diamandis, who seems to find this doublethink as amusing as she used to find her more ambitious plans. "There was an element of ‘if you say it enough, it will come true'. But at the same time, I knew it was bulls***. I was interested in the unhealthy side of wanting attention and fame, and why people have a drive to achieve something that everyone knows is a sham. And I used that to make a quite unpalatable pop album, which doesn't fit anywhere because I'm not interested in fitting in.

"I write songs to explore problems and insecurities, because that's how you get over it. So my dreams of Hollywood, I got over it. Trash pop culture, not interested any more. My visions of success, I am over it. Because I found out I don't relate to that part of the industry at all. My only cause is writing songs. My mission is to keep things interesting. And you find it interesting, or you wouldn't be talking to me. So that's a start. I have one person. Success!"

Diamandis laughs a lot, great guffaws and explosions that indicate an awareness of the ridiculousness of the whole pop process. She has the prettiness and poise of Cheryl Cole but she's more loud girl than Girls Aloud — a sharp-tongued mini-diva. She turns up for the interview wearing black sunglasses adorned with little googly eyes, black lipstick, and a black and grey "$10 vintage dress" looking, in her own estimation, like "a Victorian schoolteacher crossed with Lydia from Beetlejuice. She archly notes that, when a female pop star dresses as a female pop star should (with ridiculous, sexy flamboyance), "someone will inevitably go, ‘Oh my God! So Gaga!' Whereas, let's face it, these clothes are f***ing cool, and I'm wearing them."

Camp extravagance

Although neither as populist nor provocative as Lady Gaga, Diamandis may be her closest British equivalent. There is a quality of camp extravagance about her, and, although she arrived in a wave of female talent, with Florence + the Machine, Little Boots and La Roux following Amy Winehouse and Lily Allen, she manages to stand apart. Her distinctively zigzag vocals and staccato delivery have not been homogenised by autotune, while her musical oeuvre displays an eccentric flair that owes little to contemporary pop trends.

"I live in a bubble," she claims. "I don't like listening to radio 'cause I think it will infect my own melodies. I want to be really purist about it. So much pop is heartbreakingly bad, so bland, autotuned, identikit r&b, all singing about the same dreary things, served up like breakfast cereal. Is that what people really want?"

Diamandis attracted early media attention for a blog criticising the sexualisation of women in pop. Her song Girls managed the peculiar feat of being both feminist and bitchy, proudly asserting her equality with any man while mocking other women.

"I don't feel an affinity with girls in pop. I feel an affinity with PJ Harvey, Shirley Manson, Patti Smith, Brody Dalle from the Distillers, Juliana Hatfield, women who don't rely on their sexuality to provoke. It's a lot harder to follow an artistic route."

Diamandis insists she is making no more predictions about her future. "You can't just tell people you are good, you have to be good."

But you sense she remains privately convinced of her destiny. "The Diamonds wasn't just something cute I dreamed up. I wanted to feel part of something because I didn't fit in anywhere, so I created something where I belonged. It had an element of fantasy to it. And then it became real. So you see? It's working."

Go get yours

Marina & the Diamonds' The Family Jewels has already sold 150,000 copies.