Bernie Ecclestone told the BBC on the Silverstone grid that an unanimous agreement to revert to the Valencia regulations is "all done. It's been agreed".
Earlier, it was the case that Ferrari-powered Sauber was yet to sign the letter to the FIA confirming unanimity so that the clampdown could be repealed.
After teams meetings on Sunday morning, Red Bull's Christian Horner said: "There's no agreement."
It is rumored Ferrari, whose Fernando Alonso won the British grand prix with the clampdown regulations now in place, has also not signed the document to go back to the older rules.
"I think that we have the right direction," said an evasive Stefano Domenicali after the race.
German reports quote Horner as adding: "There is a commitment to talk about this again before Germany."