The union representing Fiji National Provident Fund workers has filed a trade dispute with the ministry of labour.
200 FNPF workers who went on strike last week after the board turned down their request for Cost of Living Adjustment, or COLA, payment for the past three years, including bonus payments.
Acting interim labour minister Adi Laufitu Malani says the FNPF board is not willing to change its stand after informal negotiation.
She says the next step is arbitration so the Union has filed a formal trade dispute.
"They have included all the initial demands, which means that it would have been better if the board had agreed to the negotiated position which was just the payment of the market salary adjustment for 2005 before Christmas."
Adi Laufitu Malani says she is out of the picture now, because the formal process has begun, so she can't guarantee there won't be further strikes.