Photo/Illutration Concrete mixer trucks are parked at a factory due to a strike by a truckers' union in Anyang, South Korea, November 28, 2022. (Yonhap via REUTERS)

SEOUL--South Korea's government on Tuesday ordered striking truckers in the cement industry to return to work, an unprecedented step that invokes tough strike-busting laws as construction sites nationwide run out of building materials.

The strike--the second in less than six months by truckers over minimum pay--is causing an estimated 300 billion won ($224 million) in losses daily and disrupting industrial activity at a time when Asia's fourth-largest economy expects a slump in growth to 1.7 percent next year.

The cement industry had estimated a cumulative output loss of about 64 billion won ($47.81 million) as of Monday, the Korea Cement Association lobbying group said.

It added that the industry had shipped about 22,000 tons of cement on Monday, about 10 percent of the usual daily shipments needed for peak season between September and early December.

In an exclusive interview with Reuters, Yoon said his government's tough response to strikes this year is starting to establish rule of law in industrial relations, which he told Tesla Chief Executive Elon Musk in a video call last week would help eliminate the risks of unfair labor practices.

Yoon administration is the first in the country's history to issue an order forcing striking transport workers back to their jobs.

Failure to comply can lead to punishments such as cancellation of licenses and three years in jail or a fine of up to 30 million won ($22,550).

Strike organizer Cargo Truckers Solidarity Union (CTSU) called the start-work order “undemocratic and anti-constitutional,” and evidence of the government's unwillingness to engage in dialogue.

“The CTSU will not yield to this pan-government crackdown,” the union said in a statement late Monday.

The union plans to hold 16 rallies nationwide on Tuesday, it added.

Government officials will conduct on-site investigations with police, relay the order to return to work, and if transport workers do not comply, suspend their transport licenses for 30 days.

If they still do not comply, licenses can be revoked, and the government can seek prosecution for potential jail time or fines, a transport ministry official told Reuters.

The government is unwilling to expand a minimum pay system beyond a further three years, while the union says it should be permanent and wider in scope.

As the strike continues, container traffic at ports dropped to 33 percent of normal levels as of 5 p.m. (0800 GMT) on Monday, the transport ministry said.