Organisers of a planned US Grand Prix in Texas have told Formula One supremo Bernie Ecclestone that they will pay a sanctioning fee for next year's race if he revises an "unrealistic and unfeasible" contract.
The 81-year-old Briton has responded by casting further doubt on the event going ahead.
Ecclestone has already made clear that he has lost patience and last week gave Austin's Circuit of the Americas a deadline of this weekend's Brazilian Grand Prix to pay the required fees and sign a contract.
