South Korean lawmakers impeach acting President Han Duck-soo

South Korean parliament voted on Friday to impeach acting President Han Duck-soo, further deepening a political crisis sparked by former leader Yoon Suk-yeol's decision to impose martial law and his own impeachment.

Han will be stripped of powers and duties until the country's Constitutional Court decides whether to dismiss or reinstate him.

He was dismissed primarily by opposition lawmakers in the country's National Assembly, who passed the impeachment motion with a 192-0 vote despite fierce opposition from the governing People Power Party (PPP) who boycotted the vote, declaring it "invalid" during a fiery parliamentary session.

Han, also the country's prime minister, was put in charge temporarily after Yoon was impeached about two weeks ago over his short-lived imposition of martial law on 3 December.

The martial law order, lifted about six hours after it was passed, shocked the country and led to Yoon's fall from grace.

The Constitutional Court has up to six months to decide whether to reinstate or remove Yoon, whose trial started on Friday.

South Korean investigative agencies are also probing whether Yoon committed rebellion and abuse of power with his marital law decree. His defence minister, police chief, and several other senior military commanders have already been arrested for deploying troops to parliament as the martial law order was in place.

Han has clashed with the main liberal opposition Democratic Party as he pushed back against opposition-led efforts to fill three vacant seats on the Constitutional Court, establish an independent investigation into Yoon’s martial law decree and legislate pro-farmer bills.

Appointing the three new Constitutional Court judges is politically sensitive, as it is these three judges who will likely approve or deny Yoon's impeachment which needs support from at least six judges to pass.

Yoon’s political allies in the PPP opposed the appointment of the three justices, saying Han shouldn’t exercise the presidential authority to make the appointments. At the same time, Yoon has yet to be formally removed from office.

On Thursday, Han said he wouldn’t appoint the justices without bipartisan consent. The Democratic Party, which holds a majority in the assembly, submitted an impeachment motion against Han and passed bills calling for the appointment of three justices.

Han’s powers will be officially suspended when copies of his impeachment document are delivered to him and the Constitutional Court. Choi Sang-mok, the deputy prime minister and finance minister, will take over in the interim.