Red Bull have called on Formula 1's new owners to introduce "simply, noisy" engines that cost below 10 million or else the Milton Keynes' squad may quit the sport.
Engines have long been an issue for Red Bull Racing as it is a customer team.
Following four championship-winning years, Red Bull's form was dealt a blow with the introduction of 1.6l turbocharged V6 engines ahead of the 2014 season.
Two years later Red Bull tried to walk away from engine supplier Renault only to learn that none of the other engine manufacturers were willing to do business with them.
— Red Bull Racing (@redbullracing) April 21, 2017
As such Red Bull would like to see an independent supplier enter F1 and the team's stay in Formula 1 could be dependent on that happening in 2021.
Asked whether he wanted to see the situation whereby teams are dependent on their supplier, Red Bull advisor Helmut Marko told the official F1 website: "Of course – and not 'one day'.
"The latest must be 2021 that an independent engine supplier comes into F1.
"This is more than necessary – and the engine has to be simple, noisy and on the cost side below ten million.
"We are talking about a much less sophisticated engine to what we have now – a simple racing engine.
"There are enough companies around that could supply.
"So we expect from the new owners together with the FIA to find a solution at the latest by the end of this season.
"If that doesn’t happen our stay in F1 is not secured."
Experience the full coverage of the FIA Formula One season throughout 2017 on FOX Sports Play, where you can watch LIVE races from angles unlike any other, highlights, interviews, behind the scenes and many more. Don’t miss it!