Police are advising motorists to avoid the anticlockwise carriageway of the M25 between junctions 28 and 27 following a two-vehicle road traffic collision which has shut two lanes.
Officers were alerted at 12.42pm today to reports of a collision between a Rover 75 and a lorry.
The collision has resulted in a leak of fuel from the lorry which has led to the current closure of two lanes.
No-one is thought to be seriously injured.
The fire service and Highways Agency are at the scene and dealing with the fuel spillage.
Congestion in the area is likely for some time.