A decisive factor is said to have been his broken relationship with team boss Christian Horner, in the wake of the power struggle that took place earlier in the year following the allegations made against him by a female employee.
This came subsequent to previous tensions, including an interview published at the end of last year where Horner said Newey’s role had changed and that "the technical team under him, led by Pierre Waché, is doing a wonderful job so they are not dependent on Adrian."
Horner also explained that Manchester United did not go under when star striker Eric Cantona left the team.
That interview did not go down well with Newey and was apparently perceived by him as Horner wanting to make himself important and minimise the contribution of others to the team's success.
Newey's wife Amanda even shared the interview on Twitter and commented: "What a load of hogwash."