The 42-year-old former Atomic Kitten singer defeated Katie Price and Peter Andre to claim the title of Queen of the Jungle in 2004.
There has been much speculation on who may participate in the next All-Stars series' gruelling Bushtucker trials, but TV star Kerry has removed her name from consideration.
According to a source who spoke to Metro.co.uk, "Kerry did have meetings to take part in I'm A Celebrity All Stars," but she was unable to do so because of other production obligations.
Kerry asked ITV executives to create an all-star series last year.
She told the Daily Star, "I'll go back in, for sure." I figured they might stage an all-star performance with the king and queens on the 20th anniversary.
The producers are also reportedly interested in Stacey Solomon, Gillian McKeith, Lady Colin Campbell, and Helen Flanagan from Coronation Street.
The new series has also been linked to Paul Burrell and Richard Madeley.
ITV unveiled the spin-off earlier this year, and Ant and Dec gave some fans a preview of what to expect.
Ant explained: "It's a spin-off from the main show, where we have ex-campmates who have all come together in South Africa, competing in challenges and trials" during a conversation with Holly Willoughby and Phillip Schofield on This Morning back in May.
He then abruptly asked his co-host, "Should I keep talking?"
"I don't think you should, I think this is a secret," Dec reprimanded him.
Dec retorted, "He's gone again, he can't stop talking!" as Ant continued to spew the rumours, with his colleague arguing that the audience "want to know."