Seoul shares opened sharply lower Monday amid deepening political chaos as the opposition-led National Assembly is pushing for another impeachment motion against President Yoon Suk Yeol after a failed bid over the weekend.

The benchmark Korea Composite Stock Price Index fell 33.36 points, or 1.37 percent, to 2,394.80 in the first 15 minutes of trading.

Yoon has faced massive pressure to step down or face impeachment after last Tuesday's shocking martial law declaration, which was quickly overturned in the National Assembly.

On Saturday, the embattled president survived the impeachment motion brought forward by the opposition bloc, after the bill was scrapped due to a lack of quorum from a boycott by the ruling party.

The opposition-led parliament is pushing for another impeachment motion against Yoon this week.

Blue chips retreated across the board, with market leader Samsung Electronics down 0.92 percent and leading automaker Hyundai Motor down 0.98 percent.

Energy and defense-related shares also lost ground. Top refiner SK Innovation fell 2.19 percent, and defense equipment manufacturer Hanwha Aerospace plunged 5.03 percent.

Battery shares also traded in negative terrain, with LG Energy Solution falling 0.51 percent and Samsung SDI dropping 1.99 percent.

The local currency was trading at 1,427.85 won against the greenback at 9:15 a.m., down 8.65 won from the previous session. (Yonhap)