Hayley said: "Having been involved in Popstars and Pop Idol, I think I have a unique insight into this fantastic event and can help ease some of the singers' tensions."
Davina McCall will be fronting the main programme on ITV1 as the search for two rival bands begins.
Battle for Christmas number one
One will be made up of five boys and the other of five girls, and it's hoped they will battle it out for the Christmas number one this year.
Popstars: The Rivals starts on Saturday 7 September on ITV1.