The 29-year-old confessed that her band mates Cheryl Fernandez-Versini, Sarah Harding, Nicola Roberts and Kimberley Walsh made the decision without consulting her.
Speaking to the Mirror, Nadine said: "On the very last night of the tour, our management and publicist came up to me and said the girls wanted to split up the band. I was thinking, 'What?!'
"I wan in hair and makeup, about to get into my costume, and the show was starting in 20 minutes. I was shocked.
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"I went back to my makeup lady and told her, and was like, 'F**k! I don't have a job! What am I going to do?' I screamed and cried on and off stage."
Following the group's split last year, Nadine tweeted: "You should know by now I had no part in any of this split business. I couldn't stop them. I had the best time & want to keep going."
Nadine also revealed that she refused to sign any documentation confirming the split, and joked that she's still in Girls Aloud.
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She said: "Thank God somebody told me the truth because I never wanted the band to split up, and afterwards they were like, 'Well she knew'. I didn't, I didn't fell it was the right thing to do. I didn't want to put my name to anything.
"So I said, 'If you want to write this thing from these four, write it from these four – but I'm taking no part in it. I never dined it, so technically I'm still in Girls Aloud. I'm a one man band!"