The rock armour will be installed south of Withernsea to protect the road between the town and the Easington gas terminal which lands 30 per cent of supplies coming into the country.
It will save hundreds of chalets as well as Newsham Gardens, a cul-de-sac to the west of Holmpton Road, and spare emergency vehicles travelling south and residents a long detour inland.
The team of civil engineering contractors from BAM Nuttall will be working on the scheme, which will culminate in barge-loads of granite rocks from Norway being installed in front of the crumbling cliffs towards the end of May.
The Holderness coastline has one of the fastest eroding coastlines in Europe.
According to council surveys, more than a metre (3.2ft) per month crumbled away in a stretch south of Withernsea between last March and December.
Ward councillor Dave Tucker, who campaigned for the scheme to go ahead, said the road was now “perilously close” to the edge.
A £3m grant, which allowed the scheme to go ahead after other bids had failed, was provided by the European Regional Development Fund at the end of last year.
The project had been placed in jeopardy following an objection from Natural England, but that was withdrawn in September.
Councillor Tucker said: “The Government has classed this as essential, because it is time-limited, and if they don’t deliver it the road will fall into the sea.
“People are very excited about it happening because a lot of people were very anxious that the scheme might be put back, and it would be lost.
“They reckon the rock armour will buy the road another 50 years.
“There’s all the infrastructure under the road – water, gas pipes, electricity and IT cables – which go south down to Holmpton, Easington and the gas terminal and Kilnsea – as well as the blue light services who use it.”
Since Roman times it is estimated that a strip of land three-and-a-half miles wide and some 28 towns and villages, along with their churches, fields, farm-houses and cottages, have been washed into the North Sea.
A former bay which was filled in during the last Ice Age, the cliffs of Holderness are made up with easily eroded materials like boulder clay.
An East Riding Council council spokesman said: “The site has been fenced off ready for work to start and the compound will be set up by the contractors in the next few weeks.
“The council is hoping construction work on the scheme will begin in a few weeks. The delivery of the rock armour is now likely to happen towards the end of May.”