The president of Bougainville, John Momis, is furious at claims by the Papua New Guinea prime minister that there is no guarantee the independence referendum will go ahead.
The vote is set to happen on June 15th in 2019.
But Peter O'Neill told parliament on Tuesday that the conduct of the vote is subject to the fulfilment of all obligations in the Bougainville Peace Agreement.
He said establishment of the rule of law, a proper government structure and the disposal of illegal weapons are yet to be achieved.
Mr Momis said Mr O'Neill was mistaken.
"Weapons disposal, fiscal self-reliance, good governance - all these things - are not conditions. They are considerations that we need to take into account in determining the date for the referendum. That's all. The referendum is inevitable. It's been decided. We will have a referendum."
Mr Momis said if Mr O'Neill acted on his comments, it would be unconstitutional and go against the Peace Agreement.
He says after the referendum is a different matter, with the international community, through the United Nations, at that stage to decide whether what is happening in Bougainville meets international best practice.