Seoul shares tumbled by nearly 3 percent 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 Korean won fell sharply against the U.S. dollar.

The benchmark Korea Composite Stock Price Index plummeted 67.58 points, or 2.78 percent, to 2,360.58, the lowest since the 2,351.83 point closing on Nov. 3 last year.

Trade volume was moderate at 583.08 million shares worth 9.84 trillion won ($6.85 billion), with losers overwhelming winners 865 to 60.

Retail investors dumped a net 888.9 billion won worth of shares, while institutions and foreign investors combined bought a net 794.3 billion won worth of shares.

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.

"The failure to pass an impeachment motion has prolonged political uncertainty," Kim Ji-won, an analyst at KB Securities, said, adding, "It will be necessary to prepare for the possibility of increased short-term volatility in the stock and foreign exchange markets."

Blue chips retreated across the board, with market leader Samsung Electronics down 1.29 percent to 53,400 won and leading automaker Hyundai Motor sliding 1.23 percent to 201,000 won.

Energy-related shares also retreated, with top refiner SK Innovation slumping 4.47 percent and Korea Zinc, the world's largest refined zinc smelter, plunging 15.33 percent to 1,535,000 won.

Financial shares also lost ground, with KB Financial dropping 2.93 percent to 82,800 won and Shinhan Financial down 1.17 percent to 50,700 won.

In contrast, No. 2 chip giant SK hynix gained 1.08 percent to 168,900 won and auto parts maker Hyundai Mobis added 2.53 percent to end at 243,000 won.

The local currency was trading at 1,437 won against the greenback as of 3:30 p.m., down 17.8 won from the previous session. (Yonhap)