Democratic Party of Korea Chair Lee Jae-myung speaks at his New Year's press conference held at the National Assembly in western Seoul on Wednesday. (Yonhap)

Main opposition leader Lee Jae-myung on Wednesday criticized President Yoon Suk Yeol and his policies, labeling them as the main contributing factors to the country's struggling economy and low birth rate.

While expressing confidence of prevailing in the upcoming general election in April, Lee also called for the restoration of the inter-Korean hotline, which was cut off by North Korea since Yoon took office in May 2022. Reconnecting the hotline would help avoid further risks of war, Lee said.

"South Korea is currently battling crises related to people's livelihood, possible war, low birth rate and democracy," Democratic Party of Korea Chair Lee said in a New Year's press conference held at the National Assembly in western Seoul.

"Our nation is crumbling under the Yoon administration's arbitrary actions and incompetence," he added.

Lee pointed to the economy's sluggish 1 percent on-year growth last year, and expressed worries that the situation may be worse than "Japan's lost decades spanning 30 years."

Though Japan has yet to announce last year's gross domestic product growth, the International Monetary Fund recently forecast the figure to stand at 2 percent.

Lee blamed the Yoon administration's decision to cut the corporate tax rate by 1 percentage point in each of the four tax brackets, which would bring the highest tax rate of 25 percent down to 24 percent, as behind the lackluster economy.

"The current administration has pushed for tax deductions for the superrich since the beginning. They claimed that it would bring about a trickle-down effect, but the reality is that it led to a shortfall in tax revenue," he said.

Trickle-down economics and its policies employ the theory that tax breaks and benefits for corporations and the wealthy will "trickle down" and eventually benefit everyone.

The Yoon administration's steps to add flexibility to the current 52-hour-workweek by giving workers the option to work up to 69 hours in a week, provided they work fewer hours in other weeks, has contributed to the country's low birth rate, according to Lee, though the plans have not gone into force yet.

"How will parents think of having children in this society (due to longer working hours and harsh labor conditions), where there is no hope and only endless competition remains," he said.

Despite the injection of some 380 trillion won ($247 billion) by the government into programs to boost the birth rate since 2006, the fertility rate continued to fall to 0.72 as of the end of last year, according to Statistics Korea. The total fertility rate is the number of babies expected to be born per woman. The statistics agency warned that it will continue to fall through 2025, eventually hitting 0.65. The replacement level for a steady population is thought to be 2.1 children born per woman.

On the inter-Korean hotline that North Korea cut off, Lee stressed its restoration must be actively pursued to reduce the risks and possibility of war. His remarks come as North Korea has been extending its provocative streak in weapons testing to increase pressure on Seoul and Washington amid a prolonged freeze in diplomacy.

Since 2021, North Korea has tested what it claims to be long-range cruise missiles fired from both land and sea at least 11 times.

"We strongly condemn North Korea, which is continuing its armed provocations in the East Sea and the West Sea," Lee said. "Chairman Kim Jong-un is throwing away the hopes of unification like an old shoe, and driving its people into misery even worse than the Cold War era."

"The Yoon Suk Yeol government must immediately restore the war-preventing hotline of peace," he said.

Meanwhile, Democratic Party Floor Leader Hong Ihk-pyo on Wednesday highlighted the party's intention to hold a revote on a special bill mandating a new investigation into the Itaewon crowd crush in 2022, which was vetoed by Yoon the previous day.

Hong said in an MBC radio interview that he is mulling holding the revote "by the end of February, though nothing is confirmed at the moment."

The revote on a special probe bill on stock manipulation allegations against first lady Kim Keon Hee could be scheduled for February as well, the three-term lawmaker added.

The bill, which aims to launch a probe into suspicions that Kim was heavily involved in a 2021 stock manipulation scandal involving local BMW dealership Deutsch Motors, is one of two special probe proposals.

The other revolves around bribery allegations against six officials accused of accepting promises of receiving 5 billion won each from an asset management firm. The allegations are tied to a controversial development project in the Daejang-dong district of Seongnam, Gyeonggi Province.

Prime Minister Han Duck-soo explained the legislation would bestow the Itaewon incident's special investigation committee with excessive power in a way that could potentially undermine constitutional principles and fairness.