Services in New Caledonia have been disrupted as the Congress is due to debate a comprehensive tax reform.
Some schools are closed, flights cancelled and many post offices shut after a call for a general strike to pressure Congress to adopt the reform.
A march organised by a union umbrella group has arrived at the Congress.
The key aspect of the reform is a planned three-tiered consumption tax which would replace a raft of levies, including the import tax.
The reform package includes a competition clause which would set a ceiling on the margin that can be charged.
The drive for the tax reform stems from years of concern about the high cost of living, resulting in massive protests and culminating in a 12-day general strike three years ago.
However, employers are opposed to the competition segment.