Pembrokeshire paragliders banned from Preseli Hills
Paragliders who have been stopped from launching from the Preseli Hills say the ban will hit tourism in Pembrokeshire.
They have been told by landowners they can no longer access the common.
Farmers say the sport disturbs their livestock while some horse riders have raised safety concerns.
But the owner of one paragliding school disputes the claims and is hoping for a rethink saying enthusiasts will be forced to go outside the county.
The two sides met at the weekend but could not reach a compromise.
The Preseli Hills are common land and access for recreation is guided by legislation called the Countryside Rights of Way Act.
The Graziers Association is representing landowners and other interests, while the access is enforced by the Pembrokeshire Coast National Park Authority.
It states paragliding is not permitted without the consent of the land owners and they have collectively agreed not to allow it.
Nick Bamber of Pembrokeshire Paragliding says the sport is growing in popularity and is worth tens of thousands on pounds to the county through tourism.
"It's a fundamentally unfair decision," he said.
"This is an environmentally sustainable sport that is a great advert for Pembrokeshire and I feel very strongly can co-exist with grazing and horse riding."
He said paragliders had used the hills for the last 20 years and he had hoped a compromise could be reached.
Mr Bamber said there were no other site in the county that could be used as often due to wind conditions, and already he was taking clients to other parts of Wales and further afield.
"I will probably end up doing a lot of my teaching abroad," he added.
No-one from the Graziers Association would comment.
However Carolyn Morgan, who runs a riding stable situated around a mile-and-a-half (2.4km) from the hills, explained her objections to sharing the hills with paragliders.
"There are bridleways all over the Preselis and everybody wants to ride on them because they are so beautiful," she said.
"But the horses take fright if they suddenly hear or see something. They will turn round and take off however old and docile they are.
"If an accident should happen while I'm leading a trek there, I am going to be liable."
By enjoying their legal entitlement to stick to the bridleways, unlike paraglider users, riders did not cause damage to wild flowers and plants, Ms Morgan added.
The Pembrokeshire Coast National Park Authority, which controls access to the Preseli Hills, said the public's right to use open countryside there, away from public rights of way, was only available to walkers.
"The legislation specifically excludes paraglider users - and those carrying out associated activities such as hang gliding - from a right of access," the authority confirmed.
A spokesperson said: "Paragliding activity carried out to date in the Preseli Hills has been undertaken without permission from the landowner.
"The National Park Authority works closely with Dyfed-Powys Police on issues where offences have been committed."
The authority said it preferred to rely on mutual agreement on the use of the land between interested parties.
But it added: "In this instance... as mutual agreement between the landowners and the paragliders has not been achieved, the authority now kindly requests that paragliders respect the landowners' position in seeking to protect the sensitive conservation nature of the site, as a Special Site of Scientific Interest and Special Area of Conservation.
"There are alternative areas within the national park where paragliding is permitted."