Paddy Lowe has left Williams.
The struggling team, whose 2019 car was delayed to the point that Robert Kubica said he is only "20pc" prepared for Australia, is calling it a "leave of absence for personal reasons".
But it is clear that Lowe, a highly regarded engineer from his earlier time at McLaren and Mercedes, is almost certainly stepping down from his role as technical director.
The Briton, who is 56, is also a Williams shareholder.
His departure might also be connected to reports that the once-great British team’s already delayed and uncompetitive 2019 car also features illegal solutions.
Reportedly, the FIA has told Williams to make modifications to the car’s mirrors and front suspension before Australia.
Former F1 driver Pedro de la Rosa told El Confidencial after Barcelona testing: "There is tremendous equality in the field this year.
"The only team that is a little off the pace is Williams."