"After the announcement, I had to go through much thinking and agony," Hwang said at the National Assembly. "I have received a great deal of messages full of criticism and disappointment from the people who gave me much support and encouragement. I felt really sorry to them."

The Bareun Party is a spinoff from the former ruling Saenuri Party, the predecessor of the Liberty Korea Party. The separation came as the Bareun Party supported the impeachment of former President Park Geun-hye over a massive corruption scandal.

The lawmakers' departure is aimed at raising the chances of a conservative presidential candidate winning the election scheduled for Tuesday next week over current front-runner Moon Jae-in of the liberal Democratic Party.

It was also apparently motivated by the lackluster support rating for the Bareun Party's presidential candidate Yoo Seong-min.

Hong, meanwhile, has seen his support rate rise sharply in recent weeks after appealing to the pro-Park and conservative base.

With Hwang's withdrawal, the Bareun Party controls 20 seats, maintaining its negotiating bloc status in parliament.

But at least one lawmaker has already expressed his intention to leave the party in the coming days.

While Hong has welcomed the defections, some members of the former ruling party have chastised the lawmakers for trying to return to a party they initially abandoned.

Aside from Hwang, one or two more lawmakers could also reverse their decisions, according to a party official who spoke on the condition of anonymity. (Yonhap)