South Korea's government says it will not negotiate with striking state power workers unless their union accepts plans to privatize the debt-ridden electricity sector. One of the country's largest labor groups is threatening to join the five-week strike Tuesday in support of the power industry employees.

South Korean Commerce Minister Shin Kook-hwan declared Monday the striking power workers should accept Seoul's privatization plans and promise not to strike over the issue. Up to 4,000 workers walked off their jobs five weeks ago to protest the sell-off plans, which they fear will lead to huge lay-offs.

Now the protest is set to widen. The Korean Confederation of Trade Unions, the more militant of the country's two umbrella labor groups, says as many as 120,000 workers will walk off the job Tuesday to support the strikers at state-run power plant companies. Teachers, taxi drivers, auto-workers and ship-builders are expected to take part in the work stoppage.

Commerce Secretary Shin downplayed the threat of wider labor unrest, predicting that there would be a poor turnout, which would ultimately help resolve the tense stand-off.

Henry Morris, a Seoul-based business consultant, agrees. "The union movement here is historically very weak and fractured. So, although one of the major union groups is calling its members out, it is very unlikely that there will be any broad-based labor strikes in sympathy with the power workers. So we are not expecting an extensive fallout from the labor dispute at the power company," Mr. Morris said.

Some cabinet members met Monday and suggested that force might be used against union leaders holed up at Seoul's Myondong Cathedral, a traditional safe haven for militant labor leaders.

The government is due Wednesday to disclose details of plans to fire thousands of power workers who ignored an ultimatum to return to work by March 25.