Local rice prices have hit the year's low at 28,900 baht a tonne for 100% premium Hom Mali variety this month.
The prices dropped by around 15% year-on-year, according to commerce ministry data.
Export prices also slipped by 18% to US$863 for Grade B Hom Mali, compared to $1,053 in November last year.
Vichien Phuanglamjiak, vice-president of the Thai Rice Farmers Association, said the group would ask the prime minister to help shore up paddy prices.
"Paddy prices for the 2014/15 crop year are now 50% lower than the pledging price of the previous government. Hom Mali paddy is sold at 9,000 to 12,000 a tonne from 16,000 while sticky paddy slid to 7,000-8,000 from 13,000 baht," he said.
Pol Lt Chareon Laothammatas, president of the Thai Rice Exporters Association, said his group had urged the commerce minister to ask some 200 rice exporters to build their stocks now, a move that could mop up 100,000 tonnes of the glut and costs 2.7 billion baht.
The 10 largest exporters have also been asked to buy 300,000 tonnes of Hom Mali rice and expand their stocks, costing 8 billion baht.