Opposition parties lashed out at President Moon Jae-in on Tuesday for appointing his pick for venture minister despite their objections, saying the decision contradicts his mantra of "cooperative politics."

Earlier in the day, Moon formally appointed Hong Jong-haak to lead the newly minted SMEs and startups ministry despite lingering criticism of his family's property inheritance and controversial past remarks.

"The appointment, despite strong opposition from the opposition parties as well as the media, is the Moon government's politics of obstinacy," Chung Woo-taik, the floor leader of the main opposition Liberty Korea Party, said during a party meeting. 

"We make it clear that all responsibilities for political trouble (stemming from the appointment) rest with the president," he added.

Kim Dong-cheol, the floor leader of the People's Party, went further, demanding the ruling Democratic Party request the cancellation of the appointment.

"We say one more time that Hong must voluntarily withdraw," he said.

"The appointment of the nominee, who the National Assembly has called unfit, is an act that ignores the opinions of the parliament as well as citizens, and it is an explicit abandonment of cooperative politics."

Cooperative politics is what Moon has pushed for to foster amicable ties with an opposition-led parliament at a time when he needs its cooperation in passing a series of bills to advance his reform agenda, such as retooling the tax code.

The ruling party called the appointment a "natural" decision, warning the opposition bloc not to politicize the issue.

Opposition lawmakers zeroed in on Hong's wife and daughter's inheritance of property from his mother-in-law, which may not be illegal but contradicts his long-held position against large transfers of wealth among relatives.

Hong has also been denounced for past comments that disparaged those who did not graduate from top-tier universities and for his past criticism of family-run conglomerates as "cancer cells" that hurt small businesses. (Yonhap)