The National Trust has said it will not lease land it manages in the Mourne Mountains for the development of a cable car up Slieve Donard, Northern Ireland’s highest mountain.

The proposed £44m project would have involved the development of a 1km cable car structure from Donard Park up to a disused quarry.

The National Trust has said the project should not go ahead in light of the “fragile and threatened” state of the Mourne landscape.

Newry, Mourne and Down District Council said the decision was “particularly frustrating”.

It said a “key aspect” of the project was to consider how best to manage visitors in the wider Mourne area, and this would include “proposed controls and interventions that would further enhance, project and restore the fragile environment”.

It added that the decision to block the scheme, which was due to receive £30m of government city deal funding, was a “huge economic loss”.

Democratic Unionist Party (DUP) assembly member Diane Forsythe said the decision could jeopardise the Belfast Region City Deal money for the area.

She said the scheme was “designed to support sustainable tourism and enhanced accessibility to the Mournes” and that the loss of funds “would be a significant setback to our local economy”.

“We cannot afford to let this opportunity slip away,” Forsythe added.

However, Alliance assembly member Andrew McMurray welcomed the move, given the “hugely significant environmental issues associated with the project, especially in light of the damage done by recent fires, as well as the serious concerns around economic viability”.

In a statement, the National Trust said its responsibility is to “restore nature in the Mournes, whilst balancing safe and sustainable access for people”.

Last month, there were almost 150 wildfires causing a devastating impact on habitats in the mountain range.

The National Trust is responsible for the land in the Eastern Mournes Special Area of Conservation including Slieve Donard and Thomas Quarry – the site earmarked for the proposed gondola station and visitor centre.

In a statement on Thursday, the trust confirmed the proposed project would “risk placing additional pressures on already degraded upland habitats”.

It would therefore “not be considering a lease at Thomas Quarry”.

The trust said it has engaged with Newry, Mourne and Down District Council on the project proposals but have “consistently expressed our serious concerns” as far back as eight years ago and “encouraged other options to be considered”.

“We have never endorsed the project and have not been a partner in its development,” it added.

The trust said its concerns about the upland habitats not being in a “favourable condition” are shared by local people.

Last year, a petition of about 6,000 signatures opposing the project was presented to the Northern Ireland Assembly.

Those behind the petition said they have environmental and economic concerns about the viability of the scheme that hopes to attract about 350,000 annual visitors.

There was also a number businesspeople who supported the project as they believed it would help create a year-round tourist economy for the region.

In a statement, Newry, Mourne and Down District Council said it was disappointed and frustrated as a “comprehensive environmental impact assessment is already under way, to consider and address the specific concerns raised by the trust”.

“A key aspect of the Mourne Mountains Gateway Project is the unique opportunity to consider visitor management to the wider Mournes area alongside the specific project location.

“This included proposed controls and interventions that would further enhance, protect and restore the fragile environment.”

It said the project had “tremendous potential to revitalise our region creating significant employment and attracting up to 365,000 yearly visitors by 2029”.

“We understand that this will be devastating for the local area which is dependent on a rural economy,” it added.

“Many locals welcomed the project to further bolster Newcastle and the Mournes as a global tourist attraction.

“We are currently engaging with the Department for the Economy and the Belfast Region City Deal (BRCD) partners to consider next steps.”