Lily Allen We have to give it to Lily Allen - she says exactly what she thinks.

And now she's gone hell for leather against another brunette songstress.

Believe us, this girl has a gift for doling out a verbal thrashing...

And this time it's Katy Perry who's come under fire.

But may we point out that Lily reckons Katy started it -  by calling her fat in the past.

Lily also slates Katy for copying Lil's own look and style.Katy Perry

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

"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."

"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 skinnier version of Lily Allen.'"

Charming. Lily clearly didn't approve of this comment, biting back:

"It's like, you're not English and you don't write your own songs, shut up."

Is Katy ready to take on the might of Lily's acid tongue?

Check out their spat, along with a ringful of run-ins, in our celebrity feud gallery down below.