CONSTRUCTION work on a £2.2bn potash mine has been delayed – but bosses say the project remains firmly on track.

Sirius Minerals has admitted diaphragm walling at its 1,000-job Woodsmith Mine, near Whitby, is two months behind schedule after bad weather and equipment commissioning interruptions knocked its progress.

However, officials today (Friday, January 12) said they are confident of making up the time, revealing a raft of sister building projects have already been completed.

The mine will extract the fertiliser polyhalite, reputed for its potassium, magnesium, sulphur and calcium content that encourages strong crop growth, with production expected to get underway in late 2021.

Sirius plans to move the polyhalite from Yorkshire to Wilton, near Redcar, on an underground transport system, and bosses today confirmed they hope to begin work on that later this year.

They also revealed the business has started clearing land at Wilton for a storage and handling plant, which will process polyhalite before it is shipped to customers from an adjoining harbour.

Although admitting the business has been affected by a delay to diaphragm walling work, which is the first phase of the mine shaft sinking process, a spokesman said the issue won’t harm its long-term progress.

He said: “The project remains on track, on time and on budget.

“Diaphragm walling activities are approximately two months behind schedule, but the company is confident this small loss of time will be recovered.

“Once the diaphragm-walling activities are completed, excavation and fit-out of foreshafts and surface basements will commence, and preparation is progressing well.

“At Wilton, site clearance and the removal of vegetation is underway, and procurement activities for the material transport system are well advanced, with a view to commencing initial construction in 2018.”

The mine is expected to create more than 1,000 direct jobs and support a similar number in the supply chain, and the company has revealed it is pushing ahead with marketplace tests to smooth its progress once fully operational.

Bosses also revealed they remain in talks with multiple global customers, having now completed 260 trials on 32 crops in 17 countries.

The spokesman added: “The company is continuing negotiations with a variety of customers in multiple regions to expand its commercial reach into new markets.”

The firm already has a stock of supply agreements in place, including a previously-announced deal with Wilmar International, which it says will see polyhalite shipped to customers in South-East Asia.