A collision that had left a lorry on its side has closed the A1(M) between Junction 44 and Junction 45.
Four people have been injured in the accident.
It happened at about 6:20 when the lorry that had been travelling southbound overturned, spilling its load on the northbound carriageway.
The lorry was carrying paper at the time of the accident.
Three people had to be freed from their vehicles. Two had suffered serious injuries. The A1(M) is not expected to reopen until about 4pm
Motorists are being warned to expect long delays, with all roads in the area reported to be heavily congested.
CCTV IMAGE - HIGHWAYS AGENCY