The Fiji Public Service Association says it's unfair that a pay cut imposed on public servants didn't extend to the interim ministers.
The interim government had placed a five percent pay cut on public servants after the 2006 coup.
Last month, it decided to restore the pay cuts in two steps but to not offer a backpay.
The union's senior industrial advisor, Nirbhay Singh, says it wonders why the measure only applied to non-ministers.
"Initially the ministers did receive a five percent reduction for one pay only but soon afterwards, by the next payday, they restored it back to normal; whereas the rest of the civil service, including all our members were reduced by five percent ever since until we found a solution."
Nirbay Singh says it has also learnt that permanent government secretaries received a bonus payment of several thousand dollars each, which it also deems as unfair.