Lorries are being stacked on the motorway again as new disruption hit Channel Tunnel services.
Kent Police initiated phase two of Operation Stack - where freight traffic is queued on sections of the M20 - at around 1am and closed parts of the road to other traffic.
The Eurotunnel passenger service was also suffering delays due to what it described only as an "incident on the terminal" at Calais. Outbound services from Folkestone were back on schedule following earlier disruption at the Kent terminal.
A statement on the firm's website said: "Our passenger service is currently operating with some timetable disruption, this is due to an incident on the terminal which is in the process of being resolved. There is a waiting time of approximately 60 minutes on the terminal.
"We sincerely apologise for the inconvenience this will cause to your journey."
Kent Police tweeted: "Op Stack phase 2 implemented due to disruption at Channel Tunnel. M20 closed coast-bound 8 to 9.
"Non-freight traffic now being allowed into Channel Tunnel terminal. M20 Junctions 11 to 12 no longer closed but delays likely. Check with operator if heading to Channel Tunnel as services disrupted.
"Apologies once again for delays and thank you all for your patience."
Ferry services were operating as normal at the Port of Dover, police said.
It is unclear whether the latest disruption is related to industrial action by French workers which caused delays earlier this week.
Lorry drivers faced days of misery as they were held in miles of queues until Operation Stack was lifted yesterday evening.
More than 3,000 hauliers were parked on the M20 after the closure of the Port of Calais earlier this week crippled Channel sailings.
The chaos was sparked after MyFerryLink workers started a wildcat strike on Monday in protest at expected job cuts in the French port city.