South Korea’s ruling party presidential nominee Lee Jae-myung is consolidating forces with heavyweights and bringing together outside forces in the tight race to presidency.

Lee's presidential election campaign committee on Monday launched a subcommittee tasked with establishing a national vision and bringing unity. The subcommittee is to be jointly headed by the presidential nominee and Lee Nak-yon, his closest rival from the primary race.

"I sincerely thank former Chairman Lee for joining me amid difficulties to fulfill the historical duty of the Democratic Party," Lee Jae-myung said Monday in an opening address to an event held to celebrate the opening of the subcommittee.

"Now is an important time to achieve unity of the people, a quintessential role of politics."

Lee Nak-yon emphasized that the party should closely adhere to the wishes of the people and share the message of innovation, empathy and unity for the presidential race. He vowed to stay close to the demands of party members and the people in his new role that follows his unsuccessful presidential bid.

"We need to organize and let people know into what kind of country we are looking to grow South Korea and how to settle peace on the Korean Peninsula," Lee Nak-yon said in his opening address.

"Based on this we need to grow our trust with the people, with which this new subcommittee will help."

The subcommittee is slated to start a nationwide campaign starting with a visit to Gwangju on Jan. 5, aiming to draft campaign promises and policy visions on the five topics of democracy, innovation, engagement, future and peace.

Lee Nak-yon’s public appearance and active involvement in Lee Jae-myung’s campaign conveys a message to nonsupporters of the Democratic Party of Korea nominee that consolidating forces is of the utmost importance in the close race against the main opposition People Power Party.

The former chief of the Democratic Party heavily denounced Lee Jae-myung in the primary race and staged a fierce battle against him up until he failed to achieve the nomination. He relinquished his lawmaker seat during the primary and even claimed unfair vote counting for days before conceding defeat.

Lee Nak-yon had mostly been uninvolved with the campaign since then, until recently meeting with Lee Jae-myung in a lunch meeting last week to officiate the opening of the subcommittee.

In a Realmeter survey of 3,090 voters commissioned by OhmyNews from Dec. 19 to 24 and released Monday, Lee Jae-myung slimly trailed main rival Yoon Suk-yeol from the People Power Party at 39.7 percent to 40.4 percent. The margin between the two candidates sharply narrowed from 6.4 percentage points from last week to 0.7 percentage point.

While the Democratic Party emphasized unity as a single team in announcing Lee Jae-myung’s nomination, it was widely speculated the party still had internal conflict raging between loyal supporters of President Moon Jae-in and those of Lee Jae-myung.

Lee Jae-myung had relatively remained in the shadows of the party until the latest race, due to his weak support base within the party and lack of experience in central politics as a lawmaker. The leftist presidential nominee had also been distanced from his party for often being critical of the Moon administration.

In the tight competition, Lee Jae-myung’s campaign team has also sought to join forces with nonparty figures to increase its chances of victory, with Democratic Party Chairman Rep. Song Young-gil calling on Ahn Cheol-soo of the minor opposition People’s Party to unite his candidacy with Lee Jae-myung.

"The most meaningful candidate from the opposition bloc is candidate Ahn," Song said Sunday in an interview with Yonhap News Agency.

"He has a support rating of 5 percent, and it will be unfortunate to see him dissipate after declaring an agenda. It will be meaningful to him to join forces (with us) and grow ideas of his own."

The Democratic Party also announced a merger agreement Sunday with its splinter Open Democratic Party, with the two parties agreeing to use the ruling party’s name after integration. The ruling party also opened its doors for former party members to return and take part in the campaign.

The ruling bloc's consolidation is believed to possibly undermine the chances of Lee Jae-myung's rival Yoon, who has been under public scrutiny for the past behavior of his wife, Kim Keon-hee.

Kim on Sunday delivered a public apology for causing controversy with allegations of falsifying her past credentials in applying for teaching jobs before and after marrying Yoon in 2012.

Yoon's campaign team has also been mired in internal conflict with People Power Party Chairman Lee Jun-seok dropping out of Yoon's election campaign committee following a heated feud with Rep. Cho Su-jin over the line of command within the party.

For more information regarding the survey results, go to the National Election Survey Deliberation Commission homepage.