Tensions are rising over the potential for a strike by Seoul Metro workers, as labor and management negotiations remain at an impasse.

Voting on a November strike began Thursday, with results to be announced Monday.

Earlier, Seoul Metro, which operates Seoul Subway Line Nos. 1 to 8 and partially operates Line No. 9, conducted 10 rounds of negotiations with a collective negotiating team representing workers, since the first meeting on July 11, but all discussions eventually collapsed.

On Oct. 4, the collective negotiation team applied for mediation by Seoul National Labor Relations Commission on the dispute. The commission is tasked with investigating the facts and making recommendations when labor unions or employers in a labor dispute seek mediation due to breakdowns in negotiations.

The commission, management and labor will hold a meeting Tuesday to seek a resolution. If the strike ballot passes and no resolution can be found, the union will announce a November strike at a press conference the following day, with a general membership meeting to follow Thursday.

Staff cuts are the main point of contention. Management, facing a substantial deficit, asserts that reducing manpower is unavoidable.

The net losses of Seoul Metro marked 1.13 trillion won ($825 million) in 2020, 964.4 billion won in 2021 and 642 billion won in 2022. Management proposed a plan to cut 2,211 employees -- 13.5 percent of the total workforce -- by 2026 to overcome the deficit.

The labor union criticized the plan, saying management is passing the responsibility for the deficits onto workers, and pointed out that excessive reduction of manpower could lead to safety concerns.

Meanwhile, Seoul Metro signed a mandatory maintenance agreement with negotiators -- an agreement that would allow employers to ask workers to return to work in the event of a natural disaster or an emergency -- on Sept. 25, to prepare against possible emergencies.