Formula One teams and Pirelli are left scrambling to find a solution to test the new 2014 tyres after rain scrapped their plans at the Brazilian Grand Prix.
Pirelli brought the prototype tyres to Brazil this weekend but teams were not able to test them because it rained during both practice sessions at Interlagos on Friday.
"I think whatever flows now has to be fair for all the teams. We're in a very delicate position," Mercedes team principal Ross Brawn said. "We all want to help Pirelli provide the best tyre they can next year but it would be unfortunate if one team had the benefit of running a tyre to the exclusion of all the other teams."
Brawn said the teams testing the tyres will have unfair access to its performance.
"I think we have to look at that very carefully, how we can do something that is fair and proper for all the teams," he said.
Ferrari team principal Stefano Domenicali said he agrees with Ross about the need for all teams to have the same information about how the tyres work. He said, however, that not testing the tyres at all could be worse.
"It will reach a point where for sure if there's no kind of test, the negative hit of not having a test will be really important," Domenicali said. "I think that in the next days we need to decide what to do for the future in this very hot topic."
Pirelli reportedly wants to run a test in December using a 2011 car.
Testing the tyres will be crucial because next year F1 will have a very different car because of significant engine rule changes that will affect the overall design.
Pirelli was disappointed but downplayed the missed opportunity at Interlagos on Friday.
"It was a pity that the drivers didn't get the chance to try the development tyres as this was an important opportunity," Pirelli motorsport director Paul Hembery said. "On the other hand, the 2014 tyres are obviously designed for a completely different type of car to what we see competing for the final time this weekend, so there was only a limited amount to learn anyway."
Sebastian Vettel was the only driver to go out with the prototype tyre - for one lap - to try to gather information, a decision seen as unnecessary by some of his Red Bull competitors.
"We always work on the principle that bad information is worse than no information," Brawn said. "With all due respect, Red Bull may well have found something out that we don't anticipate but we couldn't understand what you could learn in those conditions. It was difficult to see how it could be useful and certainly our conclusion was there was no use for us with what we wanted to do."