Katie Waissel thinks Cheryl Fernandez-Versini is a "horrible human".
The latest issue of Bella magazine is out now
The former 'X Factor' contestant - who was mentored by the 'Crazy Stupid Love' singer on the show in 2010 - has made no secret of her dislike for Cheryl in the past and has now spoken out again to accuse her of being two-faced.
Katie said: "I just thought her behaviour was shady and unnecessary - she publicly slammed me in her book without saying anything to my face but when she was my mentor, she kept trying to be my best friend and steal my cigarettes.
I personally thought she was nasty, a horrible human and completely not genuine."
The 29-year-old star added that she has no plans to settle her feud with Cheryl, 32, and warned her to keep her distance.
She told Bella magazine: "She better not dare bump into me. But I wouldn't say anything to her even if she was nice to me. I'd just be like, 'F**k off!' "
However, despite her harsh words, Katie - who now lives in Los Angeles and performs with a band named Red Velvet - believes Cheryl is doing a good job on the current series of 'The X Factor'.
She explained: "I think she's doing better this year. Last year she tried to be really controversial ... Cheryl's very concerned about the public's opinion. She wasn't hugely popular last year and that's why she's gone down the nice road on this series. I feel after this she should really take a break."
The latest issue of Bella magazine is out now.
Tagged in Cheryl Tweedy Katie Waissel