SEOUL: South Korea's ruling party, vilified for stealthily passing a controversial labor law that threatens workers' job security, offered up an apology Thursday for the nature of its passage -- but not for its content. Angry union leaders were not buying. "It is not even worth consideration at all," said Kwon Young-gil, head of an illegal labor federation spearheading the strikes. The conflict continues to heat up. Twice in the past five days, protesting strikers have clashed with police, hurling chunks of cement and brandishing pipes as riot squads lobbed canisters of tear gas. Prosecutors hinted Wednesday that they would soon order police raids on a cathedral and other sites where union leaders are taking shelter. "If the workers do not stop their illegal strikes immediately, the government will act in a firm and resolute way to protect national security," senior prosecutor Choi Byong-kuk said, suggesting that the union leaders had ties with communist North Korea. But defiant labor leaders continue to talk tough. "We are prepared for a prolonged struggle and we are confident that public opinion is on our side," Kwon said. "As the head of state, President Kim must think about saving the economy, not his face."