SEOUL -- South Korea's opposition parties began early Thursday to report an impeachment motion against President Yoon Suk-yeol to the parliament over his declaration of an emergency martial law, local TV footage showed.

The main liberal opposition Democratic Party and five other minor parties, which submitted the motion Wednesday, planned to put it up for a vote as early as Friday.

By law, the 300-member unicameral National Assembly is required to cast a secret vote on the impeachment motion within 72 hours after it is proposed.

Under the constitution, the impeachment motion must be initiated by a majority of lawmakers and approved by at least two-thirds of the National Assembly legislators.

The opposition will need eight votes from 108 lawmakers of the ruling People Power Party to get the motion passed.

If it is passed, the constitutional court will deliberate it for up to 180 days, during which Yoon's constitutional powers will be suspended and Prime Minister Han Duck-soo will be acting president.

If the impeachment against Yoon is upheld by the court, a new presidential election would be held within 60 days.

Yoon declared martial law Tuesday night before repealing it early Wednesday after the parliament voted against it. The revocation was approved at a cabinet meeting.

Meanwhile, the People Power Party lawmakers agreed early Thursday to oppose Yoon's impeachment, adopting the objection as its basic position.

The ruling party legislators refused to join the parliamentary plenary session early Thursday, in which the impeachment motion against Yoon was being reported.