Mercedes Formula 1 boss Toto Wolff says the company will not supply Red Bull with engines from 2022.
Wolff said there were “various reasons” for Mercedes to reject Red Bull.
“We are supplying four teams including us. We are almost in a state where we cannot make power units for all. There is no capacity,” he added.
Mercedes will supply McLaren, Racing Point and Williams, in addition to its factory team, from next year.
Wolff said he believed Red Bull “will have a plan B and probably doesn’t need to rely on any of the current power-unit suppliers”.
Red Bull team boss Christian Horner said the company would “take our time to do the necessary investigation and due diligence” but added that the team were limited to “the two current suppliers in the sport”.
Ferrari team boss Mattia Binotto said they had “not decided” what they would say if Red Bull approached them.
Under F1’s rules, Renault would be required to supply Red Bull if they cannot find another solution, as they do not have any customers.
The two companies had a difficult relationship through the turbo hybrid era before Red Bull joined forces with Honda in 2019.
Renault team boss Cyril Abiteboul said: “I can’t imagine they don’t have a plan and I imagine we are very far in the pecking order before they call us again.”
Horner and Alpha Tauri team boss Franz Tost said the two teams would require the same engine supplier because of the supply-chain synergies between them.
