NEARLY 30 groups representing environmental causes and national park users have joined forces in a bid to persuade park authority members to reject proposals for a £2 billion potash mine.

The 29 organisations, led by the Campaign for National Parks (CNP), have signed a letter to members of the North York Moors National Park Authority, calling for them to dismiss plans for the mine.

Members will meet on June 30 to decide whether to allow Sirius Minerals to create the mine at Sneaton, near Whitby, along with an underground conveyor belt to transport the mineral to a processing plant near Redcar.

Sirius Minerals say they are confident the exceptional nature of the project has been demonstrated and its development is in the public interest.

But the letter says the plans are not only a huge threat to the North York Moors, but a critical test of the protection provided to all national parks.

Organisations which have signed the letter include the Yorkshire Dales Society, Yorkshire Wildlife Trust, Youth Hostels Association, the National Trust, RSPB, the British Mountaineering Council and the Woodlands Trust.

The letter states: “The potential damage to the landscape during the construction phase is so substantial that Natural England has submitted a formal objection. There would also be lasting damage to the wildlife and landscape of the area.”

Last week a report by planning officers at the National Park Authority concluded that the potential economic benefits of the mine would not outweigh the environmental harm it would cause.

CNP chief executive Fiona Howie said: “The officers’ report confirms our concerns that there will be significant, harmful impacts on the sense of remoteness and the special landforms of the National Park throughout the 100 year mining period.”

Harry Bowell, director of the North region for the National Trust, said they remained "extremely concerned" about the long-term implications.

But the York, North Yorkshire and East Riding Local Enterprise Partnership has restated its support for the mine.

It has also sent a letter to the park authority, stating the economic benefits of the £1.7 billion investment, which will lead to new jobs and significantly boost the local, regional and wider national economy.

Chair Barry Dodd CBE said: “Investment on such a huge scale is unprecedented in North Yorkshire, this opportunity is one we cannot afford to miss.”