Red Bull could quit Formula 1 if the next set of engine regulations is not significantly better, top team official Dr Helmut Marko has warned.
Talks have already begun about how to tweak the controversial engine rules for beyond 2020, and Red Bull have some conditions.
Marko told El Confidencial: "The idea is very simple. We want an engine that is 1000hp, with a single standard KERS and battery, and development does not cost more than 15-20 million.
"They should have sound, and allow the driver to make the difference. And independent companies like Ilmor and Cosworth should be able to enter so that we or McLaren can use them if we want."
If those conditions cannot be met, Marko confirmed that Red Bull might quit F1.
"Yes," he said, "because last year Mercedes would not give us an engine, neither would Ferrari, and Renault was only forced by [Bernie] Ecclestone to give us one.
"We want to have an equal situation where we are not blackmailed by a manufacturer."
Red Bull currently sit third in the 2017 constructors' standings.
