A New Caledonian Kanak USTKE union representative, Pierre Chauvat, says union members plan to hold a rally later this month to protest about aspects of the two billion US dollar Goro Nickel project.
The Goro project is the biggest industrial enterprise in the South Pacific, but faces strong opposition on environmental grounds, mainly from the Kanak Caugern, Rheebu Nuu groups and the USTKE union.
In April, Rheebu Nuu activists vandalised the Goro site, causing 10 million US dollars worth of damage.
The opponents have told Goro to stop all construction by September the 24th, or face action.
Mr Chauvat says the USTKE union has now decided to have a peaceful protest.
"On the 24th September we should have a big rally there. We have decided it is going to be a peaceful rally with meetings and talks."
Mr Chauvat says the meetings between the opponents, the government of the southern province and Goro Nickel are continuing, but progress is made very slowly.
A Rheebu Nuu and Caugern representative, Jacques Boengkih, says they may take further action, but have not made any decisions at this stage.