It is "possible" that Mercedes will quit formula one.
That is the warning of F1 legend and team chairman Niki Lauda, as Mercedes now joins Ferrari in threatening to pull out after 2020.
The top teams are at loggerheads with Liberty Media over the plans for 2021, featuring different engine rules and a proposed budget cap.
Lauda told Wirtschaftswoche: "There is a limit for the top teams.
"It’s possible that one or the other will get out if it goes in the wrong direction."
Mercedes has announced that it will join Formula E in 2019.
"Only three years ago I would not have given Formula E a chance," team boss Toto Wolff told Bild newspaper. "But times have changed."
However, he said F1 remains Mercedes’ top ticket.
"Formula one is the only global platform that transports our brand," he said.