South Korea's President Yoon Suk-yeol gives a budget speech at the National Assembly in Seoul
South Korean President Yoon Suk-yeol leaves after speaking on the government budget at the National Assembly in Seoul, South Korea, 25 October 2022. JEON HEON-KYUN/Pool via REUTERS Reuters

South Korea's opposition lawmakers boycotted President Yoon Suk-yeol's first budget speech to parliament on Tuesday to protest against a criminal probe surrounding the opposition leader, in an escalating battle of wills that could complicate deliberations.

Yoon mapped out details of the 639 trillion won ($445 billion) proposal for next year to a half-empty National Assembly hall that was missing members of the Democratic Party, which holds a majority in the 300-strong parliament.

Yoon's conservative government will need the Democrats' support to fund spending on a post-coronavirus recovery and a more aggressive response to North Korea's evolving nuclear and missile threats, with a budget deadline looming on Dec. 2.

Yoon has already been weakened politically by a series of gaffes and controversies, which overshadowed his first major overseas tour last month and have knocked his approval ratings lower, inviting scathing criticism from some lawmakers within his own People Power Party.

The opposition's ire was piqued on Monday when prosecutors raided its headquarters in Seoul as part of a long-running investigation into suspected corruption involving property deals.

Several of Democratic Party leader Lee Jae-myung's former and current confidants have been arrested on charges they took more than 800 million won in illegal political contributions from developers to aid Lee's presidential campaign when it was launched last year.

Lee, who narrowly lost the election to Yoon in March, has denied any wrongdoing, while Yoon's office said it has not played a role in any criminal investigations.

The Democrats have accused Yoon, himself a former prosecutor-general, of ordering the investigation to stifle opposition. They demanded an apology, while threatening to boycott the budget speech.

Yoon refused, saying on Monday that attaching any conditions to attendance at his speech would be "unprecedented in our constitutional history".

Yoon's Tuesday speech called for swift passage of the budget with bipartisan support, to ease households' economic hardship and improve people's livelihoods.

"In order to overcome the grave economic and security situation, there can be no divide between the ruling and opposition parties," he said, adding that he "desperately needs the parliament's cooperation".

The justice minister, who oversees prosecutors' affairs, told parliament on Monday that they were looking into whether bribes were exchanged during the property development process but declined to comment when asked if they were examining the possible use of such funds to help Lee's campaign.

($1 = 1,434.9000 won)