Former ruling party floor leader Lee Wan-koo was sworn in as prime minister Tuesday after the National Assembly narrowly passed his confirmation motion a day earlier.

The 148-128 vote, with five ballots invalid, reflected the deep negative sentiment against Lee, whose qualification for the No. 2 post in the executive branch had been seriously questioned by a string of allegations of ethical lapses during last week’s parliamentary hearing. At least seven of the 155 ruling Saenuri Party lawmakers who cast ballots voted against him or abstained.

Still, the result of the vote allowed a sigh of relief to not only Lee but also President Park Geun-hye. Park had seen her two previous nominees for prime minister quit last year over allegations of ethical and other problems even before going through the confirmation process.

Failure to win parliamentary endorsement for Lee would have dealt another severe blow to Park. The president’s approval rating has fallen to record-low levels in recent weeks in the wake of scandals involving her close aides and public backlash against the revised tax settlement scheme.

Lee’s confirmation as prime minister paved the way for Park to make the long-awaited reshuffle of the Cabinet and the presidential staff, which was announced later Tuesday.

Lee is tasked with leading the Park administration’s work to reinvigorate the economy by pushing through a broad range of reforms. When he was designated as nominee for prime minister last month, he pledged to exercise full authority to be given to him and offered his “candid” views to the president.

With his reputation severely damaged by allegations of multiple ethical lapses, however, Lee was off to a crippled start as the second prime minister in the Park administration. Critics expressed concern that he may become a vegetative prime minister, as recent opinion polls have shown that most people see him as unqualified for the job.

After the parliamentary vote, Lee apologized again for controversies that erupted in his confirmation process and vowed to serve the people in a low-key attitude. His humble start, however, should not be followed up by a lethargic performance as prime minister.

He is now responsible for proving himself as a viable choice ― if not the best one ― by assuming a key role in implementing tough reforms, such as overhauling the public pension system and increasing labor market flexibility.

Hopefully, his versatile career as a senior police officer, provincial administrator and politician may help him serve in his new job. The new prime minister will have to ensure that he is viewed more favorably by the public when he leaves office.

Park also needs to give him enough leeway to carry out his work. Nearing the halfway point of her five-year term that ends in February 2018, she cannot afford to see her controversial choice for prime minister ending in failure.