Red Bull and Williams are opposed to Ferrari's request to let Michael Schumacher test in Felipe Massa's Ferrari as the seven-times world champion prepares to return to Formula One in place of the injured Brazilian.
Formula One regulations do not allow track testing during the season and there has been speculation the sport's bosses may bend the rules.
Red Bull's team principle Christian Horner says the 40-year-old Schumacher should not be treated any differently to Spanish teenager Jaime Alguersuari who made his F1 debut for Toro Rosso in Hungary last month despite previously only having driven the car in a straight line speed test.
Horner says Schumacher is a seven times world champion and has won 91 races aso he won't have a problem getting up to speed.
And Frank Williams says motorsport's governing body will set a precedent if Schumacher is allowed to test.
But so far Williams and Red Bull have received little support with McLaren confirming they wil go along with whatever the Formula One Teams Association decides.
