A traditional market in Seoul is unusually quiet on Christmas Eve in 2024. Yonhap

Calls for a supplementary budget of 20 trillion won ($13.7 billion) or more is gaining momentum in both political and academic circles, as a necessary measure to revive the country's struggling economy, which is being further strained by the ongoing political turmoil.

The main opposition Democratic Party of Korea (DPK) cited the need to allocate at least 20 trillion won in extra funding on Wednesday, arguing that the government's plan to front-load more than half of its 2025 budget in the first half of the year was insufficient.

"Such a plan is inadequate to address economic uncertainties both domestically and internationally, and to help improve the livelihoods of the people," the party said during a discussion on economic issues.

The DPK referred to the Ministry of Economy's announcement on Jan. 2 to allocate 75 percent of this year's total fiscal budget of 574.8 trillion won in the January to June period.

The ministry came up with the plan after forecasting the country's GDP growth this year at 1.8 percent — a concerning level, given that the economy has rarely grown below 2 percent.

The outlook reflects weakening growth momentum in exports and domestic consumption, compounded by political instability stemming from President Yoon Suk Yeol's Dec. 3 martial law declaration and ensuing impeachment proceedings.

"In that regard, we find 20 trillion won as a starting point for a supplementary budget to overcome economic headwinds," the DPK said.

The party explained that any potential additional spending will focus on aiding low-income and vulnerable groups, as well as supporting small self-employed businesses that are facing challenges from reduced retail consumption and rising loan delinquencies.

The DPK noted that the country may need more than 20 trillion won as a supplementary budget, to cope with the shifting international order, which is being driven by the upcoming second Donald Trump presidency.

"For instance, artificial intelligence, semiconductors and other sectors that are related to national interests require massive government support to remain competitive on the global stage," it said.

In a contribution to the vernacular newspaper, The Hankyoreh, ChungAng University economics professor Ryu Deok-hyun noted that at least 25.8 trillion won may be necessary as a supplementary budget.

The professor pointed out that the government had initially proposed a higher budget, but it was reduced by the opposition-dominated National Assembly.

"The supplementary budget should be sufficient to address the adverse effects of the ill-fated martial law and the subsequent crisis," Ryu wrote.

The professor said shortages in national tax revenues also make the extra budget crucial.

The government was expected to collect tax revenues below its projections for the second consecutive year in 2024, following a record shortfall of 56.4 trillion won in 2023. This shortfall was primarily driven by a decline in corporate tax revenues, as businesses reported lower operating profits.