A request by 12 anti-independence members of the New Caledonian Congress to approve their plan to form their own group in the legislature has again been rejected.
The Congress president, Pierre Frogier, who is the head of a rival anti-independence party, says the legislature's rules say the 12 cannot form a separate group.
The Noumea daily newspaper says an appeal court has upheld Mr Frogier's ruling after a previous court hearing had already supported Mr Frogier's decision.
This means that the rift within the Future Together Party may now leave all its members out of internal Congress commissions.
The Future Together emerged as the dominant force in the 2004 territorial election but has split into two main camps, one following Philippe Gomes and the other Didier Leroux who is the party's new president.
A member of the Gomes-led group, Philippe Michel, has said there is a basic political freedom to form a group.
The anti-independence camp has fractured into several parties which in turn have seen internal splits.
This comes as congressional elections for a new five-year term are due next year.