Debris and trees from a landslide are set to be left on the road amid an investigation into “public safety concerns”.
Folkestone & Hythe District Council (FHDC) says Folkestone’s Road of Remembrance is to remain closed while an investigation takes place.
Kent County Council (KCC) has been assessing the damage to the route since the incident on Friday night but the full scale of problems with the cliff face are yet to be established.
But the authority, which is responsible for highways maintenance, is unable to say when cars and pedestrians will be able to use it again.
Engineers from FHDC and KCC are working to assess the damage to the road and the removal of trees has been halted until further safety checks and investigations are carried out.
A KCC spokesperson said: “Until the extent of the damage caused is fully established we must keep the road closed to ensure public safety.
“We apologise for the inconvenience and thank residents and businesses for their understanding and patience.”
There is currently no timeframe for the re-opening of the road.
Danny Griggs passed the incident at 1am on Saturday on the way home from the pub.
He said: “I saw a car had stopped just ahead of us and I didn’t realise why it had until I actually got up close.
“The obstruction covered both lanes and it’s definitely a landslide, not just a fallen tree, as there is soil everywhere.
“It’ll need quite a big clean-up, it’s the main road to get from the harbour to the town.”
Metal fencing and yellow bollards have been put on the road to stop traffic.
It comes after another route in the town was closed due to a landslide.
The popular Cow Path at Leas Coastal Park was blocked by debris during Storm Ciaran three months ago and will stay shut until spring.
FHDC says it is working with consultants to “stabilise” the footpath.