Red Bull Racing is seeking clarification from the FIA about the state of the off-throttle blown diffuser regulations, after a ruling on Saturday morning prevented Renault-powered teams from being allowed to run a concession handed to them earlier in the weekend.
After an intense 24 hours of controversy over the issue, with McLaren and Red Bull Racing clashing over allowances that have been handed to their respective engine partners ahead of the British Grand Prix, the matter reached a head on Saturday morning.
Following consultation with engine representatives on Friday night, FIA race director Charlie Whiting wrote to the teams shortly before final free practice to inform them about the governing body's stance on the matter.
He told them that the FIA would stick with the position it held on the Thursday at Silverstone - where Mercedes-Benz was allowed to use an engine over-run under braking for reliability reasons relating to crank case pressure.
However, a concession handed to teams on Friday that would have allowed the Renault-powered teams, including Red Bull Racing, to run at 50 percent throttle under braking has been withdrawn. The allowance had been given to Renault because the French car maker claimed it needed to have such a level under braking to help with exhaust valve reliability.
The latest stance means that world championship leader Red Bull Racing will be forced to revert to the maximum 10 percent limit at 18,000rpm that has been imposed on all teams - so it could hurt its competitive form.
Following a series of meetings between Red Bull Racing chiefs and representatives of Renault in the paddock on Saturday morning, Red Bull Racing team principal Christian Horner and technical chief Adrian Newey stormed down to see Whiting to discuss the matter.
Although clearly angry, Horner refused to comment at length over the issue.
"I am going down to speak to Charlie about it," he told AUTOSPORT. "I am not saying anything else."
Horner and McLaren team principal Martin Whitmarsh argued over the issue in the official FIA press conference on Friday when it came to discussing the concessions handed to teams.
Horner said: "There was a technical directive which effectively turned it all off. That was obviously with reticence by the manufacturers and it has been very much a manufacture issue. Certain teams were then allowed to have fired overrun, to fuel their overrun, of which there are also, obviously, secondary benefits through the exhaust plumes and thrusts that that creates but that was permitted."
He added: "It would be unfair to allow fire overrun and not allow the same parameters for another engine manufacturer. I think it's a very, very difficult job for the FIA to pick their way through this and I think all credit to them, they've looked to try and be as fair, balanced and equitable as they decreed that they would be through the technical directive, to come up with the solutions that they have.
"We're not totally happy with the solution that we have, that's for sure. I'm sure Martin isn't with his and I'm sure there are a lot of conspiracies in the paddock that these are the reasons why Red Bull is performing or McLaren is performing, or some cars aren't performing. That's just circumstantial at the end of the day. The fundamentals are that the engine manufacturers have been treated in a fair and equitable manner."