If Red Bull fail to get a competitive engine for the 2016 season then they will quit Formula 1, that's the verdict from advisor Helmut Marko.
The four-time World Champions have struggled since the sport switched to turbo V6 engines at the start of the 2014 campaign with Renault not able to provide them with a power unit that can take on pace setters Mercedes.
Although their deal with Renault runs until the end of 2016, their working relationship is over as the French manufacturer confirmed earlier this week that they will no longer supply engines to customer teams and will either run as a works out next year or quit the sport altogether.
Red Bull, meanwhile, have been linked with Mercedes and Ferrari engines, but while the former has turned down the chance to power one of their rivals, Ferrari are open to the idea.
Marko, though, has made it clear that Red Bull won't be in F1 next year if they don't have an engine that can challenge at the front of the grid.
"The decision is done. If we don't have a competitive engine we will leave Formula 1," he told Sky Sports News HQ.
He added: "I don't want to go into details, but what's clear is we want a competitive engine, because with these regulations you saw at Monza we were two seconds behind."
Red Bull set the pace in FP2 through Daniil Kvyat in Singapore on Friday, but Marko insists they want to be there on a regular basis.
"Today we are ahead, but maybe that will change tomorrow, but we will be very near the front. As long as you don't have a powerunit that which can compete it doesn't make sense," he continued.