New Caledonia's mainly Kanak USTKE union has urged its members to vote for the Labour Party in next month's provincial elections.
The union has expressed regret that the pro-independence FLNKS umbrella group declined to include Labour on its list of candidates for the southern province.
The FLNKS position relates to last year's Labour Party decision to call on its members to abstain from voting in the referendum on independence from France.
Despite the Labour boycott call, the referendum result was closer than expected, with more than 56 percent favouring the status quo.
The USTKE union said the FLNKS' continued stance will make it much more difficult for the pro-independence side to win a majority in Congress.
The four parties making up the FLNKS run with a single list in the southern province, which is an anti-independence stronghold, in the hope of winning enough additional support to secure a majority of seats in the new Congress.
In the outgoing Congress, Labour has just one seat.