Some staff at the publicly-owned OPT post and telecommunications company in Wallis and Futuna have gone on strike.
Among the claims, unions want to know details about the revenue sharing between the company and the mobile phone company Orange.
The issues were raised in a strike notice a month ago but the unions launched an unlimited strike today after failing to get a satisfactory answer.
The public broadcaster said both the French prefect and the president of the terriotorial assembly are off island as they flew to New Caledonia for the visit of the French President Emmanuel Macron.