President Park Geun-hye on Thursday nominated a former Supreme Court justice as new prime minister in a bid to regain public confidence after the ferry disaster last month.
Ahn Dai-hee (59) will have to persuade the National Assembly that he can revamp a bureaucracy that has been blamed for creating the circumstances for the disaster and botched rescue.
One ruling-party politician said, "The public really wants a prime minister who is willing to speak his mind to the president, and President Park is well aware of this."
Meanwhile, Park also sacked National Intelligence Service Director Nam Jae-joon and presidnetial security adviser Kim Jang-soo.
Cheong Wa Dae spokesman Min Kyung-wook said the nominees for their replacement will be announced soon.
A Cheong Wa Dae official said the president sacked the key officials in order to show the government was "living up to its responsibility in dealing with the ferry disaster."
The NIS chief has been under a cloud for months after allegations that the spy agency tried to influence the last presidential election in Park's favor.