M4 long delays at Carmarthen, Swansea, Port Talbot, Cardiff and Newport as holiday congestion causes heatwave misery - live updates

There are long delays and queuing traffic on the M4 eastbound as holiday traffic builds up. According to traffic monitoring website Inrix, travel time is currently 20 minutes, with traffic queuing from junction 30 on the A4232 Pentwyn Link Road to junction 26 on the A4051.

Traffic Wales reports that it has been "a very busy afternoon", with congestion on the M4 Westbound between J23A Magor and J26 Malpas, Eastbound between J26 Brynglas and J30 Cardiff Gate and, Westbound between J38 Margam and J42 Llandarcy.

Images from the scene show queues of vehicles on the M4 near Tredegar house as holiday traffic builds up. Follow our live blog below for updates.