There are also restrictions on the westbound carriageway closing it to high-sided vehicles (height limit of 6ft 9 inches), caravans, motorcyclists and other vulnerable road users.

Traffic is being diverted in both directions via the M4 (Prince of Wales Bridge).

For more information visit our website at www.trafficengland.com, our travel 'apps' and our Twitter feed: @HighwaysSWEST or call our Customer Contact Centre on 03001235000.