Formula One's governing body has told members of the teams' association to submit unconditional entries immediately, if they are to have a say in next season's rules.
The association has submitted conditional entries dependent on the signing of a new version of the confidential 'Concorde Agreement' governing the sport by Saturday.
It wants the published 2010 regulations to be rewritten, removing an optional $100 million budget cap.
But the International Automobile Federation's president Max Mosley has written to the asssociation saying the conditions cannot be met by Saturday when the governing body is due to publish the entry list.
His advice was to enter fully, and submit their own draft rules by close of business Tuesday.
So far only Force India and former champions Williams have submitted unconditional entries although the FIA maintains that Ferrari are contractually obliged to participate under an existing agreement.
An FIA spokesman says a separate letter had been sent to Ferrari, who have threatened to pull out after an unbroken 60-year involvement.