South Korea's ruling party-controlled legislature has approved President Park Geun-hye's choice for prime minister following fierce political wrangling over whether he's fit for the country's No. 2 job.

The National Assembly passed the appointment of Lee Wan Koo in a 148-128 vote Monday. Five lawmakers abstained.

Outgoing Prime Minister Chung Hong-won offered to resign following last year's ferry sinking that killed more than 300 people. Two possible replacements abandoned their nominations because of questions over their past behaviors.

Lee, a senior ruling party lawmaker, has faced similar allegations and liberal lawmakers have demanded his resignation.

South Korea's executive power is concentrated in the president, but the prime minister leads the country if the president becomes incapacitated.