Will more F1 teams quit FOTA group?
HRT pulled out at the start of the year, with team boss Colin Kolles chiding the Geneva-based association for being "just a name and not really existing in the real world".
But it was the exits of F1's biggest budget Red Bull and Ferrari that have rocked the foundations of the body, which was set up amid the teams' political battles with Bernie Ecclestone and former FIA president Max Mosley.
"FOTA fulfilled its purpose in the crisis period," Red Bull's Dr Helmut Marko said this week, with team boss Christian Horner adding: "In the last 12 months it hasn't quite been clear what was the purpose of FOTA."
Indeed, the group has been at loggerheads over the resource restriction agreement, with accusations Red Bull breached the non-FIA pact and risked being sued by its rivals.
Ferrari is also unhappy with the direction of the cost-cutting, insisting in its explanatory note last Friday that F1 "cannot be the only professional sport where it is practically impossible to do any training".
Ferrari-powered Sauber confirmed its departure this week, and Toro Rosso – using the same Italian engine – has refused to comment so far.
The BBC reports that FOTA may actually have barred the Faenza based team's officials from attending the most recent meetings, ostensibly due to its obvious links with Red Bull and Ferrari.
Those emergency FOTA talks in the last few days have been about the future of the alliance, with Mercedes' Norbert Haug insisting on Tuesday that the association "is absolutely vital".
But it is unclear if some other teams will follow the moves of the newly-confirmed non-FOTA members, with a Lotus spokesman telling the BBC: "A lot of talks are going on but, so far, our team is still a member of FOTA."
A Force India spokesman added: "There are ongoing meetings, so it is premature to comment at this stage."