Officers are appealing for information and dashcam footage following a serious collision on the A12 in Redbridge.
Police were called at 20:27hrs on Monday, 12 April to reports of a collision involving a car and a pedestrian on the A12 Eastern Avenue, near the junction with Evanston Gardens.
Officers attended along with the London Ambulance Service and found a 40-year-old man with a head injury. He was taken to hospital where he remains in a life-threatening condition. His next of kin has been informed.
The driver of the car stopped at the scene. No arrests were made.
Detectives from the Serious Collision Investigation Unit are carrying out enquiries and are keen to hear from anybody who was in the area and saw the collision.
Anybody with information or dashcam footage is asked to call police on 101 or tweet @MetCC quoting reference CAD 6880/12Apr.