Rival parties on Tuesday reached a last-minute agreement on the renewed demarcation of electoral districts for the parliamentary elections on April 13, ending an unprecedented 54-day legislative vacuum.

But they continued to clash over the antiterrorism bill, with the ruling party and parliamentary speaker attempted to bulldoze the legislation and the main opposition party launched a filibuster to deter its passage.

Kim Moo-sung and Kim Jong-in, the respective chiefs of the ruling Saenuri Party and The Minjoo Party of Korea, met hours before the afternoon parliamentary plenary session and agreed on the final version of new constituencies under the mediation of National Assembly Speaker Chung Ui-hwa.

According to the hard-fought deal, the number of parliamentary seats through direct elections will increase from 246 to 253 and that of proportional representative seats decreased from 54 to 47.

The redrawing plan will be submitted to the National Election Commission and then to the parliamentary plenary session for a final vote as early as this Friday or next Monday at the latest.

“The agreement could no longer be delayed as the elections are drawing close,” Saenuri chief Kim told reporters.

The two parties had earlier reached a consensus on the allocation of parliamentary seats but the ruling party was adamant that other pending bills on labor reforms, service industry development and terror prevention should be passed first.

Pressed by the imminent elections and growing public criticism, however, Kim gave way and put the constituency bill on top of the list, in defiance of the party mainstream.

“The party’s official stance remains that the bills concerning the people’s livelihood should come first,” said the party’s vice floor leader Rep. Cho Won-jin earlier in the morning, before Kim closed the deal with his opposition counterpart. “No one, not even the chairman, should act against the party’s official stance.”

The nation’s electoral map lost its legal binding force as of Dec. 31 last year, due to the Constitutional Court ruling back in 2014 which decided that the constituencies should be reallocated due to unequal representation of voters.

Meanwhile, parliamentary Speaker Chung invoked his exclusive authority to submit an antiterrorism bill to a full floor vote in the afternoon plenary session.

The speaker, who had formerly refrained from using his power, recently concluded that the current diplomatic and military situations constituted an emergency situation, officials said.

The Minjoo Party set out to filibuster the plan. The party claims that the bill gives the nation‘s spy agency excessive investigative power.

“President Park Geun-hye’s forceful communication style has been passed on to the legislature leader,” said floor leader Kim Gi-juhn in a statement, vowing to deter its passage.

“The underlying intention of the bill is to empower the National Intelligence Service to interfere in the upcoming parliamentary and presidential elections, at the will of the administration.”

The revised National Assembly Act stipulates that a request for a filibuster supported by at least one-third of attending lawmakers can be submitted to the speaker, who is then obliged to allow it. The filibuster ends automatically when the legislative session ends. The ongoing extraordinary session is slated to close on March 11. The filibuster clause was introduced in May 2012 as part of the Assembly Advancement Act.

The Democratic Party, the precursor to the Minjoo, had previously made the same request in 2013 in protest to a confirmation of an appointed audit chief but was denied by then-Speaker Kang Chang-hee who said it did not apply in cases related to personnel matters.

By Bae Hyun-jung (tellme@heralcorp.com)