Detectives from the Roads and Transport Policing Command are appealing for witnesses and information following a road traffic collision in Clapham.
Police were called to the Clapham Common Northside, SW4, at 13:02hrs on Friday, 18 December,following reports of two cars being involved in collision - one car then then struck a wall.
London Ambulance Service and London Fire Brigade attended the scene.
The male driver of one car was taken to hospital where he remains in a a serious condition but stable condition. There are no other injuries.
Temporary road closures were put in place while emergency services dealt with the casualty.
No arrests have been made. Both drivers stopped at the scene.
Anyone who saw the collision or has information is asked to contact the Serious Collision Investigation Unit on 0208 5435157.