The report said 56 bungalows at Knipe Point were under threat
Engineers have recommended steps to stop a landslip which is threatening cliff-top homes near Scarborough.
Three properties have had to be demolished on safety grounds because of the landslip at Knipe Point, overlooking Cayton Bay.
A council report has described the landslip as a natural event.
Engineers have suggested building a number of concrete piles and a deep drainage channel would be the best way to shore up the cliff.
The report, which will be discussed by councillors next week, said: "The landslide, although not as active in scale as in the recent past, is ongoing and further movement could occur.
"Existing assets which may be put at risk by any future cliff recession include a section of the A165 Filey Road and 56 bungalows at Knipe Point."
Ground investigations have confirmed that the cliffs comprise of a "deep seated translational landslide system" that is "many thousands of years old", the report said.
It said only a "modest rise in the upper water table" was required to cause the landslips.
Several measures to stabilise the slope have been considered but installing deep drainage to reduce groundwater levels and the construction of the concrete piles would be the most successful, the report said.
But it said the scale of costs for the scheme would be "significant" and the work would not be possible without "extensive financial support" from other organisations and landowners.
Scarborough Borough Council's cabinet will discuss the report and decide on the way forward on 23 June.
Engineers recommended building a number of concrete piles and a deep drainage channel to shore up the cliff at Knipe Point
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