The Fiji National Farmers Union says the livelihood of more than 2,000 cane growers is in danger, with the Labasa mill to close before all the sugar has been harvested.
The Labasa mill is due to close on Friday with tonnes of cane still growing in the field.
The executive officer of the union, Roshan Lal, says he has been told the latest the mill could stay open is Christmas.
"We are looking at the livelihood of more than 2-thousand people. You know how it is going to affect...the standover cane is going to affect them in a big way. Because they have already made expenses for the production, for the fertilisers, for the land rent, for the minimal labour. And now all of that will have to be forked out from their own pockets."
Roshan Lal says negotiations are going on to try to keep the mill open as long as possible.