The case could impact on future mineral policy and affect the rate at which coal is being dug up to feed the country’s battling power stations.

The farmers, near Belfast in Mpumalanga, claim they were never consulted when government issued prospecting licences to Exxaro, South Africa’s largest black-controlled diversified-mining company and the biggest supplier of coal to Eskom.

Exxaro, whose revenue exceeded R10-billion last year, was listed on the JSE Securities Exchange in 2006, following the unbundling of Kumba Resources. Its CEO is Sipho Nkosi, who is also chairman of the South African Chamber of Mines. Vincent Mntambo, former director-general of the Gauteng provincial government, also serves on the board.

The company this week said it was aware of the legal challenge, but was confident it had stuck to all the rules and regulations set by the Department of Minerals and Energy Affairs.

Exxaro spokesman Trevor Arran said there was particular interest in coal prospecting due to the increasing demand for coal. He added: “The area has been mined for many decades. Lots of people’s jobs depend on it.”

But the farmers believe they were duped and never consulted about the mining plans, and therefore had no chance to object their constitutional right. They believe mining will have a serious impact on farming operations and contaminate scarce water resources on the Highveld. They are not against mining but believe the way it is being mismanaged is unlawful and a threat to the rural economy.

A prospecting licence allows a mining company access to privately owned land to search for minerals.

Spokesman for the group of farmers, Koos Pretorius, said mine company representatives first walked, uninvited, onto his property to test his water in 2002. “Then just after Christmas last year they called me to say they wanted to fly over my farm at a height of 50m. They said they had a prospecting licence to my land. I said that was impossible because nobody had talked to me about it.”

Pretorius is one of dozens of farmers whose land has been earmarked as a possible source of coal reserves. An estimated 3000 prospecting licences have been issued in Mpumalanga, with some even issued inside a provincial nature reserve.

The Department of Minerals and Energy has refused to disclose how many new prospecting licences were issued over the past year, despite an application for this information from an environmental group;

An international conservation project in Wakkerstroom, partly funded by the World Wildlife Fund and the Global Environmental Facility, has also been earmarked for mining, with prospecting licences already issued;

Several new black-owned mining companies are allegedly operating without valid water licences, raising major concerns about water contamination. The department refuses to confirm or deny this; and

An international report, released this week, slammed mining giant Anglo Platinum for unethical conduct and called on Parliament to revise regulations to require more consultation with landowners and communities

Despite repeated requests from the Sunday Times for comment on the issuing of prospecting licences, the department failed to respond. Ministerial spokesman Sputnik Ratau said: “At the moment it would be inappropriate for us to engage on the matter as it is before the courts.”