New Caledonia's USTKE union has called for a rally next week to denounce what it calls electoral fraud committed by the French state.
Wednesday's rally is to demand that all Kanaks be automatically inscribed on the electoral roll of those eligible to vote in the 2018 referendum on possible independence from France.
In a statement, the union said this was part of the indigenous Kanaks' struggle to attain full sovereignty while a fraudulent process was being used to sideline the Kanaks in their own country.
The protest was planned territory-wide with the main event being a march to the French High Commission.
The make-up of the roll has been a contentious issue for years.
France has promised to hold a referendum by 2018 to complete the terms of the 1998 Noumea Accord which provides for a phased and irreversible transfer of power from France to New Caledonia.