Thousands of people in New Caledonia joined a May Day march in Noumea organised by the USTKE union.
Police say 3,000 people marched while the organisers claimed 5,000 joined the rally which was also said to be a march in support of the use of the Kanak flag.
The union is urging that action be taken to fight the high cost of living, an issue which will be the focus of a rolling three-day general strike in the territory's three provinces in two weeks.
The union has said the Kanak flag won't ever be lowered because the history of the Kanak people cannot be ignored.
Last month, a movement calling for a new flag organised a march which attracted several thousand people.
The flag issue has prompted four government collapses this year.
A majority in the Congress has been in favour of the joint use of the Kanak and French flags, a practice backed by Paris since last year.