The 31-year-old blasted her former Girls Aloud band mate, who recently insisted they split up without telling her.
But Cheryl claims it was 29-year-old Nadine who wanted to pursue a solo career. The X Factor judge told Attitude: "She's full of sh_t. What d'you want us to say? She's full of sh_t.
"She was the one who wanted to make a solo record. Which is why we took the hiatus. So she's not now going to say that we broke up the band.
"She wasn't going to make another Girls Aloud record until she got a solo deal. I feel she held us to ransom and then made her solo record deal. She shouldn't tell pork pies."
Cheryl also hit out at her fellow X Factor judge Louis Walsh, who she believes implied she faked having Malaria, which nearly killed her.
She said: "It's sick. And it made me question humanity. I really lost faith in humanity for a long time.
"When I was on Piers Morgan, they had top doctors from the tropical diseases until at the hospital talking about how poorly I was. But Louis wouldn't have cared to ask anymore the facts.
"He is what he is. I accept him. He's not somebody I would call tomorrow if I was in a crisis."