The mine is planned close to the Coast to Coast route near its end in the North York Moors national park

A national park authority has received an application for the world’s biggest potash mine close to the route of Alfred Wainwright’s Coast to Coast Walk.

North York Moors National Park Authority said it believed the planning application, for the site near Whitby, is the largest ever submitted to an English national park.

York Potash withdrew its initial application last year, and submitted amended plans today.

The proposals include two mine shafts 1,500m deep and a 37km-long tunnel to convey the mined polyhalite to the Wilton works on Teesside.

Sirius Minerals, the company behind the York Potash project, wants to remove 13 million tonnes of the mineral a year from the ground below the national park. Polyhalite is used as a fertiliser.

The national park authority is seeking the public’s views. The minehead for the workings would be at Dove’s Nest Farm, less than a mile from the Coast to Coast Walk route at Littlebeck.

An authority spokesperson said: “It is anticipated that the application will be considered by the national park authority’s members at a special planning committee meeting which would be held in 2015. This meeting would be in the Whitby area to make it easier for local residents to attend.

“Since the tunnel would run through the national park and beyond its boundary to Teesside, the planning application is a so-called ‘straddling application’ with identical documents submitted to the national park authority and Redcar & Cleveland Borough Council.

“The two authorities consider the proposals in the context of national government advice and the policies for both their areas but each authority’s decision relates only to their respective part of the development.

“The authority will need to hear people’s views before making a decision and encourages residents, visitors, town and parish councils and meetings, businesses and all those who might be affected by the proposals to take the opportunity to engage in the planning process and comment on the application.”

Chris France, director of planning at the North York Moors National Park Authority, said: “The authority understands the significance of the proposals and will carefully assess the planning considerations of the development which will include the environmental impacts and economic benefits.

“We will approach the new application with an open mind and the proposed development will be determined in the context of our local plan policies and government policy which is that major development should not take place in national parks unless there are exceptional circumstances of public interest.

“I want to assure people that we will take all relevant considerations into account before reaching any decision.”

The Campaign for National Parks opposed the original application, which the company asked to be deferred while environmental concerns were considered. Sirius has changed its plans from a slurry pipeline to an underground conveyor system in a tunnel as the proposed method for transporting the mineral to Teesside. It also proposes to build an access shaft near Egton and one just outside the national park boundary.

Chris Fraser, managing director and chief executive of Sirius, said: “We believe we have a compelling planning case that clearly demonstrates that the York Potash Project can deliver exceptional economic benefits, not only locally here in North Yorkshire and in Teesside but also for the wider UK economy.

“We have planned the project with a very high regard for the environment and where possible minimising associated impacts.

“However, it is now for each authority to determine the applications according to the relevant policies and we keenly await their decisions.”

More details are on the North York Moors national park planning website.