Renault boss Flavio Briatore fears next season's switch to one make of tyres in Formula One will hand Ferrari an unfair advantage.
With Michelin departing at the end of the year, all 11 teams will use Bridgestone tyres in 2007, forcing several front runners to switch brands, including world champions Renault.
Briatore feels Ferrari, who have worked with Bridgestone since 1999, will be at an advantage as they know the characteristics of the tyres better than any of their rivals.
He said: 'I believe we need to be worried about that, absolutely. If you use Bridgestone already surely you have an advantage.
'We need to make sure that somebody working with Bridgestone in the last five years or whatever have not any advantage. The tyre is so predominant.'
Briatore called on world governing body the FIA to order a change in tyre design for next season to ensure a level playing field for all teams, even suggesting a return to slick tyres.
