South Korea's main opposition party on Sunday demanded President Park Geun-hye apologize for the deadly sinking of a ferry and lashed out at the prime minister, calling his resignation offer "utterly irresponsible."

In a press conference held less than an hour after Prime Minister Chung Hong-won announced his intent to step down over the ferry sinking, Ahn Cheol-soo, co-leader of the New Politics Alliance for Democracy (NPAD), said the president should show a sense of responsibility for the accident.

On April 16, the 6,825-ton Sewol sank on its way to the southern resort island of Jeju from Incheon, west of Seoul. Of 476 passengers aboard the ill-fated ferry, most of who were high school students on a field trip, 187 have been confirmed dead so far and

115 others are still unaccounted for.

"A sincere apology from the president will at least give a little confidence and consolation to the bereaved families of the missing," Ahn said.

He called the prime minister's resignation "not only utterly irresponsible but also cowardly."

"The prime minister and the Cabinet must first put their full efforts to manage the situation. The responsible attitude is to then apologize to the people and act according to their wishes," he said.

Both the ruling and opposition parties have suspended all campaigning for the June 4 local elections and refrained from political bickering in a show of respect and support for the victims and their families.

Kim Han-gil, the other co-leader of NPAD, also renewed criticism of the government, saying it has shown incompetence and confusion since the ship sank.

"The people have clearly witnessed the government being incompetent since the Sewol sinking," Kim said at the news conference.

"A nation who does not know that lives are precious is an underdeveloped nation, and a government that fails to protect the lives and  wealth of the people is not a government," he said.  "We have to reassess the country top to bottom, starting from the very basics." (Yonhap)