The upcoming Seoul mayoral by-election has boiled down to a two-way race between ruling party contender Park Young-sun and unified opposition candidate Oh Se-hoon. Oh, who is running on the ticket of the main opposition People Power Party, beat entrepreneur-turned-politician Ahn Cheol-soo from the minor People’s Party in a public opinion poll conducted Monday to determine the standard-bearer of the broader opposition bloc. Details of the polling results were withheld in compliance with the election law, but party officials said Oh was ahead of Ahn by a solid margin.

The winner in the election slated for April 7 will serve out the remaining 14 months of the late former Mayor Park Won-soon’s four-year term. In July, Park, who had close links to the liberal ruling party, was found dead in an apparent suicide two days after his former secretary filed a complaint with the prosecution accusing him of having sexually harassed her for years.

Both the ruling and opposition parties have high stakes in the mayoral by-election, which is seen as a major bellwether for the next presidential vote to be held one year from now.

If Oh wins, the People Power Party may have a better chance of taking back the presidency from the ruling Democratic Party of Korea. The conservative opposition party could be joined by former Prosecutor-General Yoon Seok-yeol, who has topped polls of potential presidential hopefuls since he stepped down from the post early this month. Yoon’s rising public popularity stems from his willingness, as top prosecutor, to confront the ruling camp over a series of investigations into wrongdoings involving close associates of President Moon Jae-in and possibly Moon himself.

Losing the Seoul mayoralty would deal a heavy blow to Moon and the ruling party as they face public discontent over widespread corruption, soaring home prices, increasing unemployment and the snail-paced vaccinations amid the prolonged COVID-19 pandemic crisis. Voter sentiment has recently been further exacerbated by allegations that officials at a state-run housing developer and other government agencies have made speculative land purchases by using insider information.

Moon’s approval rating fell to 34.1 percent in a poll conducted last week, the lowest since he took office in May 2017. The same survey put the ruling party’s support rate at 28.1 percent, also an all-time low since the launch of the Moon administration.

Reflecting voter sentiment, Oh, who served as Seoul mayor from 2006-2011, led his contender from the ruling party by a double-digit margin in recent opinion polls. Ahn’s support, based on a prior agreement between the two candidates to join forces, may also help consolidate Oh’s lead against Park, a seasoned politician and former minister of small business and startups.

As political commentators note, however, it is far from guaranteed that Oh will retake the mayoralty, from which he resigned a decade ago because he objected to free school meals for all students. The initiative, introduced by the then-liberal-dominated city council, gained the citizens’ approval in a poll.

The ruling bloc is going all out to rally supporters and turn around voter sentiment, especially by putting forward cash handout programs.

With a massive fourth pandemic relief package set to be distributed soon, the Seoul Metropolitan Government and heads of the city’s 25 wards -- nearly all of whom belong to the ruling party -- recently announced a plan to provide additional support worth 1 trillion won ($882 million) for people hit by the pandemic-caused economic shock, starting next month. Despite denials by city officials and ward chiefs, the hurriedly arranged support program is seen by many as an outright attempt to buy votes for the ruling party candidate.

Park has put forward her own populist pledges, including giving all citizens 100,000 won in digital currency and expanding the free meal program to cover kindergartens.

To counter the cash-propelled campaign of his rival from the ruling party, Oh will have to suggest more substantial policy measures. It will not be enough to repeat his resolution to hand the Moon government a judgment on its failures and open up the path to a change of power.

Ruling party candidate Park on Tuesday defined the mayoral by-election as a choice between Seoul’s future -- to be embodied by her -- and a “worn and failed mayor.” Voters are now urged to make the choice based on their judgment as to who can make the city a better place to live and enhance its global competitiveness, which has declined over the past few years.