Melbourne - Formula One's former commercial supremo Bernie Ecclestone has warned owners Liberty Media to take the threat of a breakaway series seriously and said Mercedes could follow Ferrari out of the championship.
Ferrari chairman Sergio Marchionne has threatened his team could quit if F1's American owners follow through on plans for simpler engines and a redistribution of prize money after contracts expire in 2020.
Ecclestone, who moved aside in January 2017 after Liberty took over, suggested both Ferrari and Mercedes, which has swept the last four drivers' and constructors' championships, were on the same page.
"Talking to people like Sergio and (Mercedes boss) Toto (Wolff), they are not idiots," the 87-year-old told Autosport.
"They will weigh up whether it's better for everyone to leave and do their own series, or do we need the (governing body) FIA to look over things? So people will start to think what to do.
"The trouble now is that Sergio has come out and said, 'The next time I see you, I'm going to punch you in the face'. And when he sees the people, he's got to be sure that he's going to punch them in the face.
"Sergio is not the guy that makes threats as a joke and then runs."
Although fierce rivals on the track, Ferrari and Mercedes are closely aligned off it on financial matters and engines - supplying six of the 10 teams in the series.
The threat of a rebel series has rumbled only days before Sunday's series-opening Australian Grand Prix.
Ferrari team principal Maurizio Arrivabene said on Friday that Marchionne knew "very well what he is talking about".
"My only suggestion is please take him seriously," he told a news conference at Albert Park.
Wolff, who was sitting alongside Arrivabene, struck a more conciliatory tone but would not rule out Mercedes leaving Formula One after 2020.
"It is clear that the current governance, how the rules are being made is not functional, there is too much different opinions and agendas on the table and we need to sort it for 2021, for the best interests of the sport," he said.
"We have at least three more years together in this great sport, regulated by the FIA, owned by Liberty, run by competent men and we just need to give our input support into the best possible way so it's great and we're not devaluing it."
Red Bull team principal Christian Horner quipped that Mercedes and Ferrari were "about the only two teams in Formula One that do agree" and said it was up to Liberty and the FIA to table a plan rather than hope for a consensus.
"My view on this is very simple, trying to get a consensus between teams that have got varying objectives, different set-ups, it's going to be impossible," he said.
"It's down to the commercial rights holder and the FIA to get together, come up with a set of regulations.
"Put it on the table and it's down to the teams whether they want to sign up to that or not."