A powerful South Korean labour union said on Sunday hundreds of thousands of its members will strike from next week against a bill that aims to curb union militancy and allow companies to hire more temporary workers. As tens of thousands of its members gathered in downtown Seoul in a show of strength, the Korean Confederation of Trade Unions (KCTU) said the strikes would begin from Nov. 26. Member unions of the country's second-largest labour group, including the union at South Korea's biggest auto maker, Hyundai Motor Co., have already voted for the strike plan. The bill, which is part of President Roh Moo-Hyun's promised labour reforms, is awaiting approval from parliament that is expected to deliberate it next week. The KCTU also opposes the government's move to sign a free trade agreement with Japan, which is likely to help Japanese manufacturers, including carmakers, gain a bigger foothold in the South Korean market. Any labour unrest will be a big headache for the government as the economy struggles to cope with depressed local demand and a negative impact from high oil prices. The Korean Government Employees' Union (KGEU), which claims a membership of 140,000, is also set to begin its first-ever strike from Monday. The government has declared that stoppage illegal. The government bans public servants from participating in union activities and KGEU is demanding the right to strike. "An illegal strike by government employees is a challenge to the government and citizens and will not be tolerated," the home affairs ministry said. "The government will pay whatever cost necessary to establish order." Police have raided union offices and detained several union leaders in an attempt to disrupt the planned strike. On Saturday, thousands of farmers clashed with police in Seoul during a demonstration against government plans to open the country's rice market.