A group of Australian grape growers wants government subsidies to help survive a crippling wine glut.

Oversupply has forced down grape prices to A$100 (US$76.29) a tonne for some varieties, or a quarter of the cost of producing the fruit. In South Australia's Riverland region on Sunday (28 May), growers demanded millions of dollars in government and industry assistance to overcome low returns.

The Riverland Winegrape Growers Association's Chris Byrne said the latest vintage produced about 300m litres more wine than was sold last year.

"If the growers themselves can then reduce their inputs and effectively mothball their grapes then there's another benefit, and that is that we're not supplying these grapes into the tanks to exacerbate what is a very, very serious oversupply problem," he told local media.

There has been no response from the government on the demands.