Access campaigners are celebrating after a national park authority was told it must remove a fence on open country.

The Welsh Assembly Government refused permission for the four-mile fence to be retained by Brecon Beacons National Park on common land. The fence runs from the Beacons Reservoir to the northern end of the Hepste Valley.

It was erected during the 2001 foot-and-mouth disease outbreak as an emergency measure. Fencing and other works are only allowed on common land with the permission of the relevant minister. The Open Spaces Society, which fought the case along with the Ramblers’ Association and the Trail Riders’ Fellowship, argued that the fence should have been removed.

The OSS’s general secretary Kate Ashbrook said: “We are delighted that the Welsh Minister has robustly refused to allow this fence to remain. It was opposed by the Ramblers’ Association, Trail Riders’ Fellowship and some individuals. It is an eyesore in this spectacular, open landscape, and restricts public access where people have the right to walk freely. It is particularly inappropriate in a national park.

“With the Ramblers’ Association, we first complained about this fence in 2002. We recognised the emergency of foot and mouth, but once that was over the fence became unlawful and we pressed for its removal. There was a general understanding that it was a temporary measure.

“However, the Brecon Beacons National Park hoped to legitimise it by getting the minister’s consent, but now this has been refused.”

Steven Jones, writing on behalf of the minister, told the OSS: “I am satisfied that the fencing is a barrier to members of the public and other commoners gaining access to the land either side of it.”

Ms Ashbrook said: “We have written to the Brecon Beacons National Park Authority to ask it to remove the unlawful fence without delay and thus restore the open, wild nature of the common for everyone to enjoy.”

A spokesperson for the Brecon Beacons National Park Authority told grough it was considering the ruling and would issue a detailed response at some time in the near future.