Korea’s 18th presidential election remains surrounded by uncertainties with only 30 days to go until the ballots are cast.

The largest variable continues to be the progressive bloc’s candidate unification that regained its momentum Sunday.

The two main progressive candidates ― the Democratic United Party’s Moon Jae-in and independent Ahn Cheol-soo ― have resolved their differences and the talks on the unified candidate selection method have resumed after a meeting between the two late Sunday evening. The process is now likely to pick up speed following the meeting, upon which the two candidates announced a joint declaration on new politics encompassing sweeping political reform measures.

The conjoined offensive by the liberal rivals that will eventually end up in a single candidacy continues to pose a double threat to frontrunner Park Geun-hye of the Saenuri Party as the race to the Blue House shapes into a battle of the conservatives versus progressives.

The highly-tense contest between Moon and Ahn, meanwhile, as they vie for the candidacy on the liberal ticket, is also likely to peak this week before their deadline on Nov. 25-26, when the final candidacy registration is to take place.

At present Moon appears to have an edge over the former academic.

According to the Gallup Korea survey for the third week of November, Moon has a 10 percentage point lead over the former academic as the favored unified progressive candidate.

In addition, Moon has seen a significant increase in the approval rating when pitted against the Park in a hypothetical one-on-one race.

In July, before the DUP presidential candidate was finalized, the approval ratings of Moon and Park had showed as much as a 20 percentage point gap in favor of the conservative candidate.

The latest polls, however, show Moon having narrowed the gap to within the margin of error or even being favored over Park.

Apparent changes in long-established political regionalism are also adding uncertainties to this year’s presidential election.

Since the early 1970s, the Jeolla provinces on the west side of the country have been a stronghold of various progressive parties that have evolved into today’s DUP, with late former presidents Kim Dae-jung and Roh Moo-hyun taking more than 90 percent of the regions’ votes in 1997 and 2002.

This year, however, Ahn is currently leading Moon with a 41 percent approval rating in the region compared to Moon’s 37 percent.

In addition, the ruling Saenuri Party is hoping to make history taking 20 percent or more of the Jeolla vote.

As with the progressive candidates, Park has placed significant emphasis on economic democratization and welfare policies, which experts say has the potential to improve her ratings in the region.

The conservatives have also recruited a large number of senior politicians with strong ties to Kim Dae-jung under the banner of achieving “national solidarity.”

The Gyeongsang provinces, the home to some of the staunchest conservatives, are showing more pronounced deviations.

Moon and Ahn respectively received 22 percent and 14 percent support from voters in Busan, Ulsan and South Gyeongsang Province, while Park’s rating came in at 49 percent.

In comparison, the region’s support for previous conservative presidential candidates came in at over 50 percent running into the late 60s.

With no clear indicators for the coming election’s results, the three main candidates are stepping up their efforts to garner support.

On Saturday, Ahn, Moon and Park all targeted the labor unions at an event organized by the Federation of Korean Trade Unions.

At the event, Park said that she will introduce measures to improve working conditions and to provide job security for those on short-term contracts. Moon approached the issue from a largely similar angle saying that he will halve the number of irregular contract workers, and that taxis will be designated as public transportation.

Ahn’s appeal to the attendants was less detailed but continued along similar lines, saying that labor unions will be given more power to establish balanced union-management relations.

On Sunday, however, the candidates’ paths diverged again with Moon attending an event organized by artists supporting him, while Ahn announced his plans to prevent unfair practices from large companies including giving small and medium-sized enterprises the right to request investigations. Meanwhile, Park announced her vision for Korea, under which she plans to focus on “national solidarity,” “political reform” and “job creation and economic democratization” if elected as president.

By Choi He-suk (cheesuk@heraldcorp.com)