Red Bull owner Dietrich Mateschitz says he needs to finalise a power unit deal by the end of October or will quit F1.
Mateschitz has been threatening to leave the sport as he seeks a competitive power unit having ended Red Bull's partnership with Renault. Mercedes turned down the opportunity to supply Red Bull, with the team now in talks with Ferrari.
With the situation dragging on and the team keen to finalise its plans for its 2016 car should it remain in the sport, Mateschitz says he needs to complete any deal within the next four weeks.
"We strive to get motors, but we get none - at least not the one we want," Mateschitz told Speedweek magazine. "The prerequisite for moving on is competitive engines."
Asked for a deadline to finalise a power unit deal, Mateschitz replied: "Sometime in late October."
Christian Horner recently described Red Bull and Toro Rosso as being in a "critical situation" regarding power unit supply.
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