*UPDATE 12.37pm*

Traffic should now be clearing on the M4 Westbound between J23A and J24.

-------------------------------------------------------------------------

THERE is significant traffic on the motorway between Magor and Newport.

South Wales Argus:

M4 Magor Eastbound (Picture: TrafficWales)

The cause of this build-up is currently unknown, but according to the AA drivers are facing severe delays of 11 minutes, which are increasing on M4 Westbound between J23A A4810 (Magor Services) and J24 A449 (Coldra).

The average speed is 10 mph.

Jo Barnes, who is currently in the traffic, said: "All the lanes are blocked solid with traffic."