Eurotunnel is warning of delays of up to two hours for freight traffic, with lorries now backing up onto the M20.
Congestion is stretching from the exit to the Eurotunnel terminal at Junction 11a back to Junction 11, for Hythe, where the slip roads are also shut because of lorries all along the hard shoulder.
Motorists are warned of delays as a result.
Meanwhile, reduced services at Dover due to limited P&O services has seen Dover TAP activated with lorries queuing on the A20.
The system is designed to ease the flow of freight traffic into the town when demand increases.
National Highways says it expects the situation to ease later this morning.
All freight traffic should travel in the left hand lane, with cars using the right hand side.