The chief executive of Peace Parks Foundation, Werner Myburgh, said: "We are all deeply concerned about the lack of vision, guidance and leadership in managing the whole mining issue in South Africa.
Coal mining at Vele would lead to other developments which would further encroach on the national park, a world heritage site, and the Greater Mapungubwe Transfrontier Conservation Area.
If 300 60-tonne trucks are right on the edge of the national park, there's no doubt in anybody's mind it will significantly impact on future tourism development."
A coal-fired power station was also planned, and heavy industrial activity would put future tourism at risk.
said the park would make a much more significant contribution to the South African economy than a short-term capital injection with a lifespan of 29 years.