Christian Horner has confirmed Red Bull is yet to formally enter F1 as a power unit supplier after the deadline for submissions was again altered.
F1 will race under a set of revised power unit regulations from 2026, changes that have encouraged Audi and Porsche to join the grid.
Audi will partner with Sauber, the team currently racing as Alfa Romeo, but Porsche is yet to complete an arrangement after talks with Red Bull broke down.
It had been hoped a partnership would avoid the setup costs associated with creating an F1 facility after the team launched its powertrains department last year.
The championship-winning team is creating its own power units for the introduction of the new regulations, with AlphaTauri also set to benefit from the latest technology.
Asked to provide an update on the situation, Horner said: “The deadline has been extended again. Until mid-November at the moment.”
Pressed further on whether Red Bull has formally lodged its entry, Horner added: “Not yet.
"It has been delayed for the reason that there are still elements regarding the governance and the regulations that are being tidied up. That affects everybody, not just Red Bull.”
The original deadline for entries was August 31, with Audi announcing its intentions at the Belgian Grand Prix five days before this date.
The deadline was then extended to mid-October, prior to the latest mid-November date.