Protesters shout slogans at a candlelight protest demanding South Korean President Park Geun-hye step down over a recent influence-peddling scandal in Central Seoul, South Korea, November 16, 2016.[Photo/Agencies]

SEOUL - South Korean President Park Geun-hye embroiled in a scandal involving her longtime confidante saw her approval rating fall further to the lowest since her inauguration in February 2013, a local pollster survey showed Thursday.

According to a weekly survey of 1,525 adults conducted by Realmeter from Monday to Wednesday, support for Park was 9.9 percent, down 1.6 percentage points compared with the previous week.

It was the first time that Realmeter's poll recorded Park's approval rates below 10 percent in about four years in her office. Another pollster Gallup Korea's survey showed the president's support rate at 5 percent, the lowest for two weeks in a row.

Falling support for Park came as the president Blue House refused the rising demand for voluntary resignation, shown in last Saturday's protest rally that drew about 1 million South Koreans in capital Seoul alone.

According to the Realmeter poll, 73.9 percent of respondents said Park should step down or be impeached to take responsibility for the political scandal. It was higher than 60.4 percent the previous week.

Park's attorney had requested the delay of investigation into the president though prosecutors claimed the need for face-to-face questioning no later than Wednesday.

It is highly unlikely to see the prosecution office directly investigate the first South Korean female leader in the foreseeable future as Park's decades-long friend, Choi Soon-sil, is expected to be indicted on Sunday.

Choi, 60, whose friendship with the president dates back to the 1970s, was arrested on suspicions of meddling in state affairs behind the scenes and peddling influence for personal gains.

Negative assessment on Park's governance increased 2.0 percentage points to 85.9 percent this week, the highest since she took office in early 2013.

Approval rating for Park's ruling Saenuri Party broke the record low under the Park administration at 18.2 percent this week, down 1.0 percentage point from a week ago. The downward trend continued for seven straight weeks.

The Minjoo Party, the country's biggest opposition party, posted support rate at 30.5 percent, while the cast vote-wielding People's Party recorded its highest 17.0 percent in public support.