SEOUL, Jan. 10 (Reuters) - South Korea's main opposition party leader, Lee Jae-myung, said on Wednesday he hoped a stabbing attack he suffered could mark the end of the "politics of hate" in the country.

He was speaking to reporters and supporters after he was discharged from a hospital in Seoul, where he has been recovering since last week's attack in the southern city of Busan.

"I hope this case which shocked everyone can serve as a milestone to end the politics of hate and confrontation and restore proper politics," said Lee, who thanked medical staff at the hospital and vowed to serve his country.

The attack was widely condemned as an "act of terror" and a challenge to democracy by President Yoon Suk Yeol and politicians from both the ruling and opposition parties.

Police are due to announce the outcome of an investigation into the attack later on Wednesday.

Earlier, the alleged assailant told reporters he was sorry over the fallout from the attack as he was leaving a police station.

Three members of the main opposition Democratic Party announced they would leave the party citing disagreements over Lee's leadership while wishing him a swift recovery.

Though the Democratic Party and Yoon's conservative People Power Party account for the majority of lawmakers in parliament, a number of politicians on both sides of the aisle have indicated they plan to break away to form new parties to run in general elections due in April.