Christian Horner warns that Renault will walk away from F1 unless it is allowed to develop its engine next year.
Whilst the Red Bull team boss' call doesn't come as a surprise, eyebrows will surely be raised since it is his team that has been most publicly critical of the French manufacturer this year.
Such was the Renault's uncompetitiveness this weekend, for once even Daniel Ricciardo lost his smile, though it was Max Verstappen, at sister team Toro Rosso who became the first to take a grid penalty for exceeding the allowed four units.
Ironically, whilst it has often been felt that Renault has never fully exploited its successes in F1, now that things are not going so well the French manufacturer is very much in the firing line.
Next year, its last under its current deal with Red Bull, Renault is seeking to be allowed to develop its power unit over the course of the season, but Mercedes, which powered seven of yesterday's top ten finishers, is standing firm keen to stick to the current rules that requires unanimous agreement between the teams for the regulations to be relaxed.
Such a move, warns Horner, will drive Renault out of the sport.
"The situation is we are at a precarious point in terms of Renault's commitment to the future," he told reporters in Montreal. "If you are effectively shutting that down in February, you are almost waving goodbye to them," he added, referring to the pre-season (2016) engine freeze.
"So Mercedes need to have a bit of a grown-up think about it. And the FIA as well to say what is in the best interests of F1. If F1 can afford to lose an engine manufacturer, then stick to Feb. 28."