The former Williams and McLaren technical chief has grown increasingly frustrated with his role at Red Bull, as well as being affected by a fractured relationship with team boss Christian Horner following an internal investigation into alleged 'inappropriate behaviour'.
It is unknown what sort of challenge the Brit will embark on next, but it has been suggested that he has four teams chasing his signature, according to Autosport.
The likes of Ferrari (who are long-term admirers of his work), Aston Martin, McLaren and Mercedes could all afford his services.
Aged 65, he could also decide to leave Formula 1 all together, having spent a long time at the pinnacle of motorsport.