Biffy Clyro's Simon Neil has told Justin Bieber to stop classing himself as a rock star.
The 'Wolves of Winter' hitmaker is frustrated that pop singers who don't write their own music think they are worthy of the lofty title and he doesn't understand why anyone would want to listen to the 'Sorry' hitmaker's music.
The 36-year-old rocker said: "For some reason a lot of pop stars are being called rock stars and are even calling themselves it.
"The problem with Bieber is he has teams and teams of people making his music for him so how can he be one when he doesn't make his own bloody music? I don't get why people like him. I don't like Bieber."
However, Simon has no problem with Kanye West hailing himself "the greatest living rock star" at the Glastonbury Festival last year, because the 'Bound 2' rapper actually has a "personality" and creates his own art, although he still wouldn't bestow the title on him.
In an interview in the Metro newspaper, Simon said: "I love Kanye. I wouldn't call him a rock star but he is more of a conceptional artist - he has a character and a personality, so I understand why people listen."
Simon and his Biffy Clyro bandmates, Ben Johnston and James Johnston, will release their seventh studio album 'Ellipsis' on July 8.