The main opposition Democratic Party (DP) vowed Monday to go all-out in its campaign to reform the state intelligence agency, continuing their outdoor protests but launching a full-scale participation in parliamentary affairs.

The move comes nearly two months after the DP took to the streets and set up a temporary office in tents outside Seoul City Hall, demanding President Park Geun-hye overhaul the National Intelligence Service (NIS) amid allegations that it tried to influence last year's presidential election.

Until Monday, the opposition had effectively boycotted the regular parliamentary session that began early this month as part of its protest campaign.

"I ask all (DP) lawmakers as chairman never to leave the National Assembly until all parliamentary audits of government offices are over, unless it's to do with our outdoor protest, sleep at the Assembly, study and prepare fiercely for the parliamentary audits and devote yourselves to our struggle within parliament," Rep. Kim Han-gil, the DP leader, said at a general meeting of DP lawmakers.

He then instructed DP floor leader Jun Byung-hun to begin talks with the ruling Saenuri Party on the timetable for the current parliamentary session, including the dates for the parliamentary audits.

Kim also vowed to strengthen the outdoor protest, saying he would lead protests nationwide along with DP members of local councils and regional party chapters.

The DP's moves come after a three-way meeting with Park and the ruling and opposition party leaders last Monday failed to produce a breakthrough in the parliamentary impasse. (Yonhap News)