Shareholders of fertiliser producer Sirius minerals approved the first tranche of funding for the vast project yesterday.

Now preparation works including further geotechnical studies on site are due to begin immediately.

Highways improvements are scheduled to begin in the new year, with the detailed site preparation works targeted to start after April next year.

Russell Scrimshaw, Sirius chairman, said: “Today’s successful General Meeting concludes the Stage 1 Financing and delivers a major milestone for Sirius Minerals.

“The financing has taken a huge amount of work and dedication from everyone at the company and also from those that support our business.

“We are now focussed on the construction programme ahead and the path to first production for our North Yorkshire polyhalite project.”

The decision will come as a big boost to the civil engineering industry in the region and to the Murphy/Hochtief joint venture which is in line to build a 23-mile tunnel to transport minerals from the mine head site at Dove’s Nest Farm near Whitby to a portal near the town of Redcar.

The stage 1 funding will cover the direct costs of all site preparation, mine shaft excavations, tunnel caverns, project management and owner costs as well as provide certain contingency funds for the project.

Cash will be released over the first three years after commencement of construction.

Designed by Arup, the plan is to use five hard rock TBMs, which will be lowered in at four intermediate staging shafts. The starting depth will be around 360m below the surface at the mine head

A further £1.5bn will be needed two years into initial construction to fund Murphy/Hochtief’s tunnelling contract, mine fit-out and harbour facilities at Teesside.