Saenuri lawmakers also refused to take part in the 20-day audit that kicked off this week, disrupting normal proceedings.

"If the ruling and opposition parties face can't agree on key issues, it is the role of leaders to try to resolve the problems," Rep. Woo Sang-ho, the floor leader of the Minjoo said, adding a hunger strike cannot be the solution.

Woo also urged Saenuri lawmakers to return to the National Assembly and join audit proceedings.

Rep. Park Jie-won, who heads the minor People's Party, added Lee's strike will only add to the confusion in South Korean politics.

Saenuri lawmakers' protest came after South Korea's opposition parties passed a motion to dismiss a Cabinet minister over alleged ethical lapses, while the ruling party boycotted the vote and walked out of the session.

The Saenuri and the presidential office have argued the dismissal motion was politically motivated and had nothing to do with the actual wrongdoings of the Cabinet minister.

Chung, who is originally from the Minjoo, fueled the debate when he was heard in a voice recording saying that the ruling party should not "ask something for free," indicating the speaker may have wanted to utilize the dismissal motion to induce Saenuri to make concessions on other issues that are important to the opposition.

Chung left the opposition party after being designated as the speaker under South Korean law. The voice recording, accordingly, further sparked concerns of Chung's willingness to remain neutral on parliamentary affairs. (Yonhap)