SEOUL, Korea, Republic Of -- South Korean President Park Geun-hye entered what could be her last day in power Friday, as lawmakers geared up for what's widely expected to be a successful impeachment vote amid a corruption scandal that has left her isolated and loathed.

The opposition feels confident that they'll get an impeachment Friday, the last day of the current parliamentary session, because dozens of members of Park's ruling party have said they'll vote against the woman who was once their standard bearer.

It's possible that the vote could be delayed or fail, but lawmakers from both parties face huge pressure to act against Park, the daughter of a military dictator still revered by many conservatives for lifting the country from poverty in the 1960s and 1970s.

Once called the "Queen of Elections" for her ability to pull off wins for her party, Park in recent weeks has faced millions of South Koreans who have taken to the streets in anger over what prosecutors say was collusion with a longtime friend to extort money from companies and to give that confidante extraordinary sway over government decisions.

Her approval ratings have plunged to 4 per cent, the lowest among South Korean leaders since democracy came in the late 1980s, and even elderly conservatives who once made up her political base have distanced themselves from her. An opinion survey released Thursday showed about 78 per cent of respondents supported Park's impeachment.

If the impeachment vote happens Friday and passes, the country's constitutional Court will have up to 180 days to determine whether to formally end Park's presidency. During that time Park would be suspended as president but not removed, with her duties, including commander in chief of South Korea's 630,000-member military, temporarily transferred to the prime minister until the court reaches a decision on whether her impeachment is constitutional.

Park's confidante, Choi Soon-sil, and two former presidential aides allegedly linked to the scandal have been indicted. Park, who has immunity from prosecution while in office, has refused to meet with prosecutors investigating the scandal.

Park, South Korea's first female president, would be the country's second leader to face an impeachment vote. In 2004, lawmakers impeached then President Roh Moo-hyun on allegations of incompetence and election law violations. But the impeachment led to a big public backlash, and the constitutional Court reinstated Roh two months later. Roh left office in early 2008 after serving out his single five-year term. In 2009, he killed himself amid a high-profile corruption investigation of his family.

Park has publicly apologized over the scandal three times and acknowledged that she received help from Choi in editing her speeches and with unspecified "public relations" matters. But she denies involvement in Choi's alleged criminal activities.

About 160 lawmakers affiliated with the two main opposition parties said Thursday that they would resign en masse if parliament does not approve Park's impeachment, but that might be just symbolic because the parliamentary speaker won't likely approve the resignations out of worries about further political chaos.

Park's father, Park Chung-hee, ruled the country for 18 years until his 1979 assassination. Choi is a daughter of Choi Tae-min, a purported cult leader who served as a mentor for Park Geun-hye until his death in 1994. Park, whose mother was assassinated in 1974, described Choi Soon-sil as someone "who helped me when I had difficulties" in the past.

Park's ties with Choi Tae-min, who was mired in corruption scandals, have long dogged her political career. Many here criticize her for maintaining ties with the Choi family and for what's seen as a lack of transparency on the key decisions she has made.

Park, whose term is to end in early 2018, tried to fend off impeachment by saying she would stand down if parliament arranges a stable power transfer. Her liberal opponents called the overture a stalling tactic to buy time and find ways to survive the scandal.