Horner denies Red Bull teams sign up for 2010
Like fellow independents Williams and Force India, who have already lodged their paperwork and will appear on Friday's FIA entry list, Red Bull and Brawn GP are not subject to the same $50m bond that is holding together the unity of the remainder of the FOTA group.
Williams and Force India were expelled from the Formula One Teams Association, but the defection of Red Bull Racing and Toro Rosso would leave the alliance weakened with just six members: all car manufacturers.
Red Bull mogul Dietrich Mateschitz's loyalty to FOTA has been questioned from the very beginning of the dispute with Max Mosley, as he is a close personal friend of the FIA president.
But Horner, team principal of Mateschitz's senior F1 team, shot down the speculation, telling motorsport-total.com that it is "not true at all".
However, it remains possible that the Red Bull outfits – as well as Ferrari – will be listed along with Williams and Force India on the FIA entry list, due to the teams' apparent contractual arrangements with the sport's ruling bodies.