After announcing it would scrap rice import caps from next year, the South Korean government proposed on Thursday an initial 513-percent tariff to soften the impact on a crucial domestic market.
For the past two decades, Seoul has maintained quotas on foreign rice imports under a deal it secured with the World Trade Organisation (WTO).
But with the deal set to expire at the end of this year, the government announced in July that it would open the market, while promising angry farmers that it would set the highest permissible tariffs.
"We will propose (to the WTO) a tariff of 513 percent ... to protect the local rice market," Agriculture Minister Lee Dong-Phil told a parliamentary agriculture committee meeting on Thursday.
The rate will have to be verified and confirmed by the WTO -- a process that could take months.
Rice imports are an extremely sensitive political issue among rural voters who fear they would eventually be pushed out of the market by cheap foreign imports.
Rice farmers warn the tariffs will swiftly be cut back as the result of free-trade deals with rice-exporting nations.
The current agreement with the WTO provides for mandatory rice imports, which this year will amount to nearly 410,000 tonnes -- or around 10 percent of consumption.
Farmers' organisations have always met any slight policy change with angry protests, and a small group of activists picketed Thursday's meeting.
Holding banners saying "No to opening of the rice market!" they threw eggs and pepper powder at the members of the parliamentary agriculture committee.