South Korea's three opposition parties are set to make an official report on the impeachment motion against President Park Geun-hye later Thursday at the National Assembly in regards to her alleged involvement in a corruption scandal rocking the country.

The report on the motion will pave the way for a vote Friday, with the fate of the president to be decided by the country's Constitutional Court.

The opposition parties handed in the motion to parliament last week, saying that Park violated the Constitution and other laws by allowing her confidante Choi Soon-sil to exert power in state affairs and enjoy unlawful benefits. State prosecutors have accused Park of being Choi's accomplice.

A successful passage calls for approval from at least 200 lawmakers from the 300-seat National Assembly. Accordingly, at least 28 lawmakers from the ruling Saenuri Party must give it a nod, even if every single opposition and independent lawmaker votes for the impeachment.

A group of non-Park lawmakers in Saenuri said it has secured support from around 40 lawmakers, but uncertainties remain, with some casting doubts on the level of support.

While the group earlier asked the opposition parties to exclude the sinking of the Sewol ferry, which left more than 300 dead or missing, as one of the grounds for Park's impeachment, the main opposition Democratic Party said it has no intention to do so.

The opposition parties claim Park failed to protect the safety of the people as stipulated by the Constitution.

The Park dissenters' group said it will continue to persuade the opposition parties, adding the issue remains one of the major hurdles for Saenuri's participation in the motion.

Lawmakers of the Democratic Party said they will resign en masse if the impeachment fails to pass the parliament on Friday.

Rep. Woo Sang-ho, the Democratic Party's floor leader, said the announcement reflects its members' determination.

Members of the splinter People's Party also said they will step down if the vote is rejected.

Park loyalists at Saenuri continued to protest the motion, adding the parliament should instead seek a peaceful resignation for Park.

"It is still not too late to stop the impeachment, and have Park step down in April and hold the presidential election in June," Rep. Lee Jung-hyun, the Saenuri chief emphasized.

National Assembly Speaker Chung Sye-kyun said the parliament will not be open to the public Friday as requested by some opposition lawmakers but said he will consider allowing protests at the front gate.

Once the motion is passed, Park will be barred from the management of state affairs and her powers will be handed over to Prime Minister Hwang Kyo-ahn.

Among the key authorities of the president as stipulated by the Constitution are the control over the military, the right to clinch treaties with other countries, and the power to exercise vetoes.

Following the passage of the impeachment motion, the Constitutional Court will then review its legitimacy, with the proceedings to take upwards of 180 days. Park earlier said she will wait for the outcome, ruling out the possibility that she will step down voluntarily.

In 2004, the National Assembly passed an impeachment motion for late former President Roh Moo-hyun, although it was later turned down by the Constitutional Court.

During the court's proceedings, Park will still receive the same protection and support as president. Her paycheck will also remain the same, although some duty-related expenses will be cut.

If the impeachment is approved by the court, Park will not be able to receive the benefits provided to former presidents. By law, former presidents are provided with pension, secretaries, drivers and medical coverage. An impeached chief executive, on the other hand, would only receive security protection. (Yonhap)