TOKYO: Most Japanese want a new prime minister to lead rebuilding after last month's earthquake and tsunami, newspaper polls showed Monday, as the head of government was again scolded in parliament for his handling of the nuclear crisis that followed. Japan is struggling to bring the Fukushima Daiichi nuclear plant under control after it was crippled by the March 11 natural disasters, a process that could take the rest of the year. Plant operator Tokyo Electric Power Co. (TEPCO) said on Sunday it hoped to achieve a cold shutdown to make the reactors stable within six to nine months. That timetable will only be met if “everything goes smoothly”, Chief Cabinet Secretary Yukio Edano said. The full recovery could take even longer and rebuilding the shattered northeastern coast has yet to begin. The cost of material damages alone from the quake and tsunami has been estimated at $300 billion, making it the world's most costly natural disaster. More than 13,000 people have been confirmed dead, and tens of thousands made homeless. Nearly 70 percent of people surveyed by the Nikkei business daily said Prime Minister Naoto Kan should be replaced, and a similar number said the government's response to the nuclear crisis was not acceptable. Kan was criticized again in parliament on Monday for his response to the nuclear disaster. An opposition lawmaker suggested he had been ill-prepared from the start, pointing to Kan's admission that he could not recall the details of a drill last year that simulated a Fukushima-type incident. “Prime Minister Kan is working hard and he must be experiencing difficulties. But many people have questions about Prime Minister Kan's leadership,” opposition Liberal Democratic Party (LDP) lawmaker Masashi Waki told the upper house budget committee. Kan said he and his government were doing their best. “Japan has experienced many crises in the past, but I believe this is the biggest crisis in the 65 years since the end of World War Two,” he told a parliamentary panel on Monday. “From now on ... we must persist with our strategy on two fronts, and I want to make every effort on both issues,” he said, referring to rebuilding the country and resolving the nuclear crisis.