Ferrari and Red Bull Racing have decided to withdraw from the Formula One Teams' Association as the result of the ongoing dispute over the sport's Resource Restriction Agreement.
Amid ongoing debate about the future of FOTA, with teams failing to agree to a way forward for the RRA after a meeting at the Brazilian Grand Prix, both Ferrari and Red Bull Racing have lodged notification that they intend to leave the organization.
It is understood that both teams wrote to FOTA earlier this week to inform them of their decision. Neither Red Bull Racing nor Ferrari would comment on the situation beyond Ferrari's official statement confirming its move.
A spokesman for FOTA confirmed only that the body had received notice from two teams that they no longer intended to be a part of it, but would not elaborate on which teams they were.
"FOTA confirms it has received the resignation of two teams," said a spokesman. "While considering its next steps, FOTA will continue to work on behalf of its members to achieve the aims of the organization."
FOTA's latest statutes mean that teams must give a two-month notice period to leave the organization, which means Red Bull Racing and Ferrari will officially depart the body by the start of February next year – providing they do not change their mind.
Ferrari has viewed a deal over the RRA as key to FOTA's future, with Ferrari team principal Stefano Domenicali warning earlier this year that if a deal could not be reached to sort out cost controls within FOTA then the future of the body should be called into question.
Speaking at the Korean Grand Prix, Domenicali said: "If this [mistrust] will come out of FOTA activity, then what is FOTA all about? We know the reason why FOTA started, and now we need to understand if FOTA is still needed. What are the objectives of the future of FOTA, if there is a future for FOTA?
"We need to do that in a very constructive way, a very open way. That is the discussion that I believe in the next weeks is important to have."
Red Bull Racing team principal Christian Horner said at the same race: "I think that FOTA has reached the crossroads where it needs to deal with some of the key issues moving forward or we'll stop. It's as simple as that.
"The principal issues are obviously the Concorde Agreement, the direction that goes in, and fundamentally the RRA (Resource Restriction Agreement). If we can't find agreement within FOTA on that, then what is the purpose of FOTA?"