Seoul, August 02 (Saba) - The chairman of the main opposition Democratic Party (DP) in South Korea resigned Monday over the party's defeat in last week's parliamentary by-elections, the party spokesman said, shaking up the political bloc riddled with internal feud, according to Qatar News Agency (QNA).

Chung Sye-kyun stepped down after the DP's rival, the ruling Grand National Party (GNP), scored an unexpected victory in the extra polls by winning five of the eight seats in the July 28 by-elections, South Korea's news agency (Yonhap) reported.

"I feel moral responsibility for the disappointing result in the by-elections," Chung was quoted as saying at a party leadership meeting.

"I decided to step down to promote stability of the party and a fair management of the upcoming leadership race, with the belief that it would not be appropriate to protract the party's feud," he said, according to party spokesman Woo Sang-ho.

Opponents within the party had been demanding his resignation, blaming his unwise selection of candidates as the cause of the defeat.

Last week's losses hit harder after the DP's stunning victory in the June 2 local elections in which it won most of the key mayoral and gubernatorial seats.

The ongoing internal dispute, meanwhile, is likely to deepen over whether the entire party leadership should resign to assume collective responsibility.

Woo said the party's supreme council will meet within days to discuss how to fill the leadership vacuum after Chung's resignation.

Under party rules, Kim Min-seok, a council member who gained the most votes after Chung in the last party leadership race, would assume the chairmanship. But Chung's opponents insist that the current leadership step down en masse and that the party form an "emergency management committee" until new leaders are elected.

Saba