Formula One's governing body has urged champions Ferrari to take the lead in agreeing to a cost cap for 2010 after the Italian team made their opposition evident.
In an exchange of letters seen by Reuters, International Automobile Federation (FIA) head Max Mosley rejected a suggestion by Ferrari president Luca di Montezemolo that the budget cap would result in a "fundamentally unfair and perhaps even biased" championship.
"I hope Ferrari will take the lead in agreeing the cost cap mechanism, thus freeing its engineers to work and preserving its shareholders money," Mosley wrote.
He pointed out that the championship, which has already lost Honda, was fighting for survival.
"As you know, we are in an unprecedented situation," Mosley wrote in a reply to Montezemolo dated April 29 and quoting Sergio Marchionne, chief executive of Ferrari's parent FIAT.
"The car industry and financial services are the two main sources of Formula One income. Both are in serious difficulty. We cannot just sit and wait, hoping nothing bad will happen.
"We have already lost one manufacturer. Despite my repeated requests, not a single manufacturer has given us a legally-binding undertaking that it will continue in Formula One," added the Briton.
"We may lose another manufacturer team at any moment. We already know that the current levels of expenditure are unsustainable for the independent teams. The matter is therefore extremely urgent."
The FIA announced on Thursday that teams agreeing to compete in the 2010 championship with a cost cap of £40 million would be given greater technical freedom than those remaining with unlimited budgets.
The measures included unrestricted engines, movable front and rear wings and a KERS system, which gives a short boost at the press of a button, twice as powerful as those used by uncapped rivals.
The reaction from teams was cautious, with some backing a cap but opposed to what would effectively be a two-tier championship.
Montezemolo wrote to Mosley on April 28 expressing reservations and complaining that Ferrari had been given little time to assess the proposed new regulations before the FIA's world motor sport council met on Wednesday to approve them.
Montezemolo, who expressed doubts about the fairness of creating "two categories of teams" and warned of creating confusion in the public mind, said he did not see why the rule changes had to be rushed through. The Ferrari president also told Mosley that Ferrari, the sport's most successful team, had guaranteed rights and insisted on them being respected.