Unionized Seoul subway workers opposed to their company's downsizing plans are set to end a two-day "warning" strike Friday evening but threatened to go on a general strike sooner or later unless their demands are met.

The latest strike was launched Thursday by the biggest of the three labor unions of Seoul Metro, the operator of subway lines 1-8, in protest of the city-run company's bid to reduce its workforce by 13.5 percent, or 2,212 employees, by 2026 to address its chronic deficit.

The temporary walkout is scheduled to end at 6 p.m. Friday.

But the largest Seoul Metro union affiliated with the militant umbrella Korean Confederation of Trade Unions threatened to stage a general strike sometime after the nationwide college entrance exam set for Nov. 16, as long as there is no change in the positions of the Seoul city government and their company.

The threat was unveiled during a rally of striking workers in western Seoul on Friday morning.

"Our struggle is not over yet. Let's be fully prepared to start a general strike if our demands are not met," union leader Myung Soon-pil said at the rally, adding the exact date of the second strike will be determined later.

Seoul Metro saddled with a cumulative deficit of 18.4 trillion won ($14 billion) has said downsizing is inevitable to normalize management, while the labor claims a drastic cut in the workforce could lead to safety issues.

The company reportedly offered to increase the number of new recruits this year by 272 to 660, but the KCTU-affiliated union rejected the proposal. (Yonhap)