Railway workers who launched a work-to-rule protest this week over the government’s restructuring plans have announced an indefinite strike starting December 5.

At a press conference Thursday, the Korean Railway Workers’ Union said the government’s push to reduce the workforce by some one-thousand-500 people has worsened the labor shortage.

The union also accused the management of attempting to outsource the operation of most train routes.

The workers are demanding a bigger workforce and a wage hike of two-point-five percent.

Earlier, the Korea Railway Corporation classified the work-to-rule protest as a slowdown and warned of a stern response if any laws were broken.

The main union at Seoul Metro, which operates the city’s subway lines 1 through 8, is also expected to begin a walkout on December 6 after an ongoing work-to-rule protest, unless labor and management reach a deal on restructuring and a wage hike.