The emergency services are at the scene amid reports that one vehicle has overturned.
Road users are advised to allow plenty of extra time for their journeys and may wish to consider an alternative route if possible.
Drivers wanting to continue southbound should follow the ‘hollow square’ diversion route.
Accident investigation is currently underway and normal traffic conditions are not expected to resume until the early hours of the morning.
More will follow on this story as and when we get it.