Australian mining company Frontier Resources says Prime Minister Kevin Rudd could end up with egg on his face if his government backs the "weak" case for the Kokoda Track to be added to the World Heritage list.
The company fears World Heritage listing would prevent its plan to mine copper and gold on a section of the historic track in Papua New Guinea.
The Rudd government wants UNESCO to protect the site where Australian troops died fighting Japanese troops during World War II.
Local Koiari landowners back the mining plan because they say tourism and trekking provides little or no financial support for villages on the track.
Frontier managing director Peter McNeil says the case for World Heritage listing is weak.
He says there is no cultural value and historically Kokoda is only valued by Australia, PNG and Japan.