South Korea’s Constitutional Court said it will rule on whether to formally dismiss or reinstate impeached President Yoon Suk Yeol on Friday.

It has been deliberating on Yoon’s political fate over his ill-fated imposition of martial law that triggered a massive political crisis.

The won reversed earlier losses to turn higher against the US dollar after the announcement of the ruling date.

The stock market's benchmark KOSPI was up 1.5 percent after the announcement of the ruling, after pairing earlier gains to 0.5 percent.

The court, which currently has eight justices with one seat vacant, can decide to oust Yoon only when six or more judges agree, according to South Korea's constitution.

Whatever decision is, it will likely deepen domestic divisions.

Millions have rallied in Seoul and elsewhere to support or denounce Yoon in the past few months.

Police said they’ll mobilise all available personnel to preserve order and respond to acts of vandalism, arson and assault.

The opposition-controlled liberal National Assembly in December voted to impeach Yoon, a conservative, leaving his political fate in the hands of the Constitutional Court.

Yoon is facing a separate criminal trial after he was arrested and indicted by prosecutors in January on rebellion charges in connection with his December 3 martial law decree.

The Constitutional Court’s endorsement of Yoon’s impeachment would officially drive him out of office and prompt a national election within two months to find a new president.

If it overturns Yoon’s impeachment, he would immediately return to his presidential duties.

At the heart of the matter is Yoon’s decision to send hundreds of troops and police officers to the assembly after imposing martial law.

Yoon has insisted that he aimed to maintain order, but some military and military officials have said Yoon ordered them to drag out lawmakers to frustrate a floor vote on his decree and detain his political opponents.

Yoon argues that he didn’t intend to maintain martial law for long, and he only wanted to highlight what he called the “wickedness” of the main liberal opposition Democratic Party, which obstructed his agenda, impeached senior officials and slashed his budget bill.

During his martial law announcement, he called the assembly “a den of criminals” and “anti-state forces.”

By law, a president has the right to declare martial law in wartime or other emergency situations, but the Democratic Party and its supporters say South Korea wasn’t in such a situation.

The Democratic Party-led impeachment motion accused Yoon of suppressing parliament's activities, attempting to detain politicians and others and undermining peace in violation of the constitution and other laws.

Yoon has said he had no intention of disrupting National Assembly operations and detaining anyone.

Yoon’s martial law lasted only six hours because lawmakers managed to enter the assembly and vote to strike down his decree unanimously.

No violence erupted, but live TV footage showing armed soldiers arriving at the assembly invoked painful memories of past military-backed dictatorships. It was the first time for South Korea to be placed under martial law since 1980. (AP/Reuters)