His desire to leave Red Bull was first reported by Germany’s Auto Motor und Sport, but the information has been independently verified by BBC Sport with high-level sources close to Red Bull and Newey.
They confirmed that his desire to leave stems from his unhappiness over the situation involving Horner, which has led to a multi-faceted power struggle at Red Bull.
The team cleared Horner of wrongdoing after an internal investigation. The complainant, who has since been suspended, has appealed against the decision.
Horner and Red Bull motorsport adviser Helmut Marko are in dispute, as are the Thai main shareholder Chalerm Yoovidhya, who backed Horner, and Red Bull Gmbh in Austria, who had initially wanted to remove him from his position.
Newey has been at Red Bull since 2005 and has overseen two dominant eras with the team, from 2010-14 when they won four consecutive drivers’ and constructors’ titles with Sebastian Vettel, and the current era with Max Verstappen.
Last year, Verstappen and Red Bull produced the most dominant season in F1 history, the Dutchman winning 19 of the 22 races and the team all but one. They look on course for a similar performance after winning four of the first five races this season.
Newey has previously had multiple championship-winning success at both Williams and McLaren.
As Red Bull’s chief technical officer, Newey is no longer working full time on F1 – he is also involved with the company’s other projects, such as the forthcoming RB17 supercar.
And Horner has on occasion emphasised the strengths of the team under Newey, led by technical director Pierre Wache.
But the design chief remains the brilliant mind responsible for the concept of the team’s successful cars and his departure will represent a seismic blow.
It may also further unsettle Verstappen, who is known to have his own misgivings about the internal situation at the team.
Verstappen, who is under contract to the end of 2028, has been asked on a number of occasions to offer his full backing to Horner and has always given equivocal answers.
But he has repeatedly emphasised his desire to keep the senior team at Red Bull in place, and said at the Chinese Grand Prix last weekend: “I signed a long deal. The only thing I said from the beginning is we want to have a peaceful environment, lately we have been talking about the car.
“I am happy about that, I am happy with the team and there has never been a reason to leave.”
Verstappen is contractually able to leave if Marko loses his position – and the driver was instrumental in keeping the Austrian in place when it emerged at the Saudi Arabian Grand Prix in March that his position was under threat.
He is not believed to have the same freedom in the event of Newey leaving, but he would regard the departure of such a totemic and influential figure as a major loss.
Mercedes are openly courting Verstappen and hope to lure him away for 2025 or 2026.