Main opposition Democratic Party Chairman Lee Jae-myung speaks at a New Year's press conference at the National Assembly in Seoul on Jan. 12. Yonhap

Opposition leader Lee Jae-myung lashed out at the government of President Yoon Suk Yeol on Thursday for what he called an attempt to "annihilate" the opposition party amid a prosecution investigation into bribery allegations involving him.

Lee, chair of the main opposition Democratic Party of Korea (DPK), also renewed his calls for one-on-one talks with Yoon as he held his first official press conference, just two days after he was questioned by prosecutors over the bribery allegations.

"I hope for a halt to the scheme to annihilate the opposition party," Lee said. "So far, the government has been bent on destroying the opposition party and killing a political enemy while talking about cooperative governance."

Lee accused the prosecution of "doing politics" instead of "investigation," saying the prosecution questioning was "very unfair" and "unjust."

Lee said his offer of talks with Yoon still stands.

"I have already proposed talks with the president many times. The proposal is still valid now," he said.

On pending issues, like the economy and security, Lee claimed what he called the "Korea risk" is escalating amid tough economic circumstances and security issues spurred by the recent infiltration of North Korean drones in Seoul.

"The economy has entered what seems to be an endless tunnel of hardship," he said. "The president's risky bomb of words to cover up his incompetence in handling security has only amplified people's concerns and market confusion."

The DPK leader criticized Yoon's recent remark on the possibility of South Korea's own nuclear armament, saying, "It should never happen, is unrealizable and only an act of escalating tensions on the Korean Peninsula."

Yoon made the remark during a joint policy briefing from the foreign and defense ministers Wednesday, saying if Pyongyang's provocations intensify, "The Republic of Korea could deploy tactical nuclear weapons or possess its own nukes."

On the issue of whether the Constitution should be revised to improve the country's power structure, Lee said he supports changing the current single five-year presidency to a four-year presidency with the possibility of reelection one time.

The long-standing debate has gained traction again recently after the National Assembly Speaker Kim Jin-pyo said he will push for establishing a special parliamentary committee for a constitutional amendment.

In South Korea, the president or parliament can propose a constitutional amendment, which must be approved by a two-thirds majority in the assembly and then by a majority in a national referendum in which more than half of eligible voters participate.

Past attempts to revise the 1987 Constitution, which limits the presidency to a single five-year term, have failed due to a political power split between a powerful presidency and a fractious parliament.

"The Democratic Party of Korea will come up with its own bill to revise the Constitution by March," Lee said, calling for a national referendum at a parliamentary election to be held next year. (Yonhap)