Farmers say Queensland's fresh milk supply will shrink in the next decade if retailers don't charge more per litre.
A handful of farmers from across the state's southeast rallied outside the Coorparoo Coles in Brisbane's south on Wednesday, demanding the retail giant support them by lifting its price.
Woolworths has bumped the cost of its own-brand milk by 10 cents a litre, but Coles has refused to follow suit because it might burden customers.
But Harrisvale farmer Ross McInnes says doing so would only cost consumers an extra $8 a year.
Mr McInnes runs 400 to 500 cows on a family farm that's been operating for 104 years, and says the costs are enormous.
Drought has led to soaring grain prices, making it more expensive for farmers to feed their herds on top of costs like water and power.
But during the last decade the price per litre of milk has gone down, squeezing the industry further.
"At the moment there would be 1.6 million Queenslanders who are now drinking milk produced interstate, that weren't in 2010," Mr McInnes said.
He says the future looks bleak without change, with regional households more likely to be hit if fresh milk becomes scarce.
"We've got 370 dairies in Queensland at the moment, that could get down to 150 in eight to 10 years' time, and there will be more imported milk," he added.
Five families work on Colleen and Mark Platell's Beaudesert farm, where 300 cows are milked twice a day, every day.
They say 10 cents is the difference between getting by and making a profit, but have invested too much to pull out.
"There's not a dairy farmer in Queensland or NSW as far as that goes, that wouldn't have considered it," Mr Platell said.
"The consumer has to realise that if we go out of business, there will not be fresh milk for them, they'll be drinking UHT milk."
Coles' decision to stand firm on its price drew the ire of federal Agriculture Minister David Littleproud, who urged a boycott.
However he refused to back a bid by Labor in federal parliament for a mandatory minimum milk price, saying it was an outdated stunt.
