The incident happened at the A40 Western Avenue between Swakeleys Roundabout and Denham Roundabout close to Uxbridge.

The collision was on the westbound carriageway just before the road becomes the M40, and has resulted in two lanes being blocked. This is causing heavy traffic around the immediate area with congestion reported in Hillingdon and at the Polish War Memorial, close to the junction of West End Road in Ruislip.

At present it is not known if the accident has resulted in any casualties.

Earlier this week, two people were taken to Hillingdon Hospita l after another incident involving three cars on the A40 at Hillingdon Circus.