Loud mouth Lily Allen has dug her claws into Katy Perry, branding the perky popstar a phony for not writing her own songs.

Lily has toned down the catty remarks lately but, with a new album on the way, she's throwing herself back into the deep end with a rant about Katy.

She told Capital FM, "When I met her I was 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!'.

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

Over to you, Katy...

See Katy's loud style below