A ruling party lawmaker who had contact with a COVID-19 patient earlier this week tested negative for the coronavirus Friday, prompting the National Assembly to move forward with a plenary session to review the government's extra budget as planned.

"I was notified that my test result came back negative. I apologize for causing concerns today," Rep. Oh Yeong-hwan of the Democratic Party told reporters through a text message.

Oh underwent testing and quarantined himself earlier in the day after learning that he shook hands with a person who had COVID-19 at an event in Uijeongbu, Gyeonggi Province, on Wednesday.

Regardless of the negative result, the freshman legislator, a former firefighter, said he plans to remain in isolation for two weeks.

Amid the news of Oh's contact with the patient, the National Assembly was placed under heightened alert earlier in the day, with the Democratic Party ordering its lawmakers who met Oh to remain inside their offices.

Oh was believed to have had contact with some 100 people, including lawmakers, parliamentary aides and National Assembly staff.

The news also prompted the National Assembly to reschedule a slated plenary session to approve the government's third extra budget to 10 p.m.

The session could have been postponed to a later date had Oh's test result returned positive.

The plenary session was convened to review the government's third extra budget of 35.3 trillion won ($29 billion), meant to help key industries cushion the economic blow from the pandemic and protect jobs.

Ahead of the plenary session, the parliament's budget subcommittee passed a revised budget of 35.1 trillion won, slashing 200 billion won from the government's proposal.

Rep. Lee Nak-yon, former prime minister and the front-runner in polls among potential presidential candidates, had suspended public activities and went into quarantine at home.

Lee returned to the National Assembly to attend the plenary session after learning of Oh's test results. (Yonhap)