The Daily Star claims that the pair will replace current presenters Matt Willis and Emma Griffiths, who are expected to focus on parenthood after discovering that they are expecting their first child together.
Van Day commented: "I always thought we were the new Ant and Dec. But hey, the new Matt and Emma? That's fine by me."
The former popstar finished in fourth place on Celebrity earlier this month. Meanwhile, Mallett was the fourth contestant to be eliminated.
I'm A Celebrity is expected to return for its ninth series in November next year.