Bernie Ecclestone has revealed that Red Bull thought that they had an engine agreement with Mercedes in July, only for the deal to fall through.
Red Bull are currently without an engine supplier for the 2016 season after cancelling their agreement with current partner Renault.
Possible partnerships with VW and Ferrari have come to nothing while McLaren have said that they don't want Honda to supply any other teams. As a result, Red Bull face a very uncertain future as they look to find an engine that will make them competitive, not just keep them on the grid.
Ecclestone has explained that Red Bull have found themselves in this predicament in part because they took talks between Ecclestone, Red Bull team principal Christian Horner, Mercedes motorsport chief Toto Wolff and its non-executive chairman Niki Lauda as a solid sign that Mercedes would provide them with engines.
"In defence of Red Bull, or Christian in particular, the reason they cancelled their agreement with Renault is so they could do the deal they thought they had done with Mercedes," said Ecclestone.
Lauda has also revealed that Red Bull owner Dietrich Mateschitz never followed up on talks on the matter.
The Austrian said that Mercedes were interested in the partnership as they want "young Red Bull kids driving Daimlers", but that Mateschitz "never came back, so the discussions never really started, and the whole thing died away."
It's not only Red Bull's future that is in question, with Renault also in doubt despite announcing plans to take over Lotus.
"You'd have thought they'd have made up their mind before now," Ecclestone said of Renault. "When I spoke to the president (of Renault), he said they would make an announcement in December."