New Caledonia's pro-independence FLNKS has threatened to challenge the outcome of the next referendum because of the use of the French flag by the anti-independence camp.
A majority in Congress voted for a provision to allow the tricolore to be used in campaign material ahead of this year's vote on independence from France.
But the FLNKS said if approved by the French state, it would introduce a bias and risked undermining the outcome of the plebiscite.
By law, French political parties are not allowed to use the tricolore in their material as not to convey the notion that they represent the state.
However, Paris said it in the referendum context it would create a balance because the FLNKS movement was using its own flag.
An FLNKS politician Jacques Lalie said the policy was anti-democratic because it suggested that those wanting independence were not French.
The vote was set for 6 September but because of the Covid-19 pandemic the prime minister proposed deferring it to 4 October while Congress suggested to reschedule it on 25 October.
In the previous referendum, in 2018, just under 57 percent voted for the status quo.
Should voters again reject independence this year, another referendum can be called by New Caledonia's Congress within the following two years.