Lily Allen has slammed Katy Perry, accusing the singer of being nothing more than a “crass” American version of her.

Allen said Perry had only won a record contract because her American record label was looking to exploit Allen's appeal in the US.

The singer also accused Perry, who shot to fame in the summer with the hit 'I Kissed A Girl', of not writing her own material

"I happen to know for a fact that she was an American version of me,” Allen told Capital FM.

“She was signed by my label in America as, 'We need to find something controversial and kooky like Lily Allen.' And then they found her... I think the lyrics and stuff are a bit crass.”

Allen added: "When I met her I was a bit frosty with her because someone asked her to describe herself.

“She's like, 'Aha, I'm like a fatter version of Amy Winehouse and a skinner version of Lily Allen!'. It's like, you're not English and you don't write your own songs, shut up!"

(by Jason Gregory)