Officers were called at 10.52pm last night (21 May) by Cambridgeshire Fire and Rescue Service to reports of a collision on High Street, Knapwell.
The collision involved a black BMW 330 which had collided with telegraph poles and overhead power lines.
The driver of the BMW, a man in his 30s, has been taken to Addenbrooke's Hospital with life-threatening injuries and remains in critical condition.
The passenger in the car, also a man in his 30s, has also been taken to hospital with minor injuries.
Anyone who witnessed the incident or saw the BMW prior to the collision should call police on 101 quoting incident 461 of 21 May.