Welsh government proposals to change the way Wales’ moorland is classified are set to face a judicial review next month.
The government is being challenged over its decision to split Wales’ moorland in two by introducing a 400m altitude line.
Under the proposals land above the line will paid €20/ha (£16/ha), while land below the invisible line will receive €200/ha (£160/ha).
The legal action has been brought about by more than 100 Welsh hill farmers, who said it was unfair 45% of Welsh moorland situated lower than 400m will receive almost 90% of the money allocated to the moorlands.
They said hundreds of hill farmers faced losses of tens of thousands of pounds due to the proposals, potentially making many hill farms unviable.
Sheep farmer Tony Davies, who farms 680ha in the Elan Valley, Powys, said his support payments would be considerably lower under the new scheme.
“The unfairness of the proposal is already creating huge rifts between neighbouring farms within mountain areas due to the huge shift of money,” he said.
“In some cases, farmers on the same mountains with identical habitats will receive ten times less support per hectare than their neighbours.”
Mr Davies, who together with more than 100 other farmers raised the money to fund the legal action, said the rules would put hill farmers at a competitive disadvantage both locally and nationally.
“We’re facing an even more unlevel playing field because England has increased its moorland rate to €70/ha [£56/ha] after five years at €45/ha [£36/ha],” he said.
The group had spoken to former farm minister Alun Davies, who understood the devastating effect the proposals would have on Wales’ upland areas and made a commitment to help farmers, Mr Davies added.
However, since the minister was replaced by deputy farm minister Rebecca Evans, the government’s response had left them no choice but to take legal action.
A Welsh government spokesman said the government was unable to comment until the legal process had run its course.