"Lee Jae-myung won't die. Democracy won't die. The future of this country won't die," Lee said as he attended an anti-government rally calling for a special probe into allegations involving first lady Kim Keon Hee, in central Seoul, Yonhap news agency reported.
Stressing that he has followed the path of former President Roh Moo-hyun, Lee said since entering politics, he has worked hard to root out corruption and hold accountable those who are unjust.
"Rather than being an individual Lee Jae-myung, all I have wished is to become a loyal tool for the people of this country and I have wanted nothing more," he said.
Lee's remarks, which appeared to be an apparent appeal of his innocence, came just a day after the Seoul Central District Court said Lee was guilty of making false statements in violation of the Public Official Election Act and sentenced him to a year in prison, suspended by two years.
If upheld, the ruling will strip him of his parliamentary seat and bar him from running in the 2027 presidential election, in a development that could put the main opposition on thin ice and reshape the country's political landscape.
Lee has vowed to appeal, saying he found even the "basic facts" presented at the ruling "hard to accept."