Tokyo: A recent poll in Japan indicated on Monday that nearly three quarters of Japanese voters are unhappy with the centre-left government's handling of the Fukushima nuclear power plant disaster.

The survey came days before Prime Minister Naoto Kan faces a threatened no-confidence motion by the Conservative opposition, which is unlikely to pass but nonetheless presents a fresh political headache for him.

The Nikkei financial daily said in its survey that 74 percent of respondents were unhappy with the Kan government's management of the nuclear crisis, up from 70 percent in a survey in April.

Public support for Kan's cabinet stood at 28 percent, compared to 27 percent in April, the Nikkei said.

The phone survey was carried out from Friday to Sunday, covering 1,513 voters, of whom 59.4 percent gave valid responses, in regions across Japan excluding areas hit hard by the March 11 quake and tsunami.

Tokyo Electric Power Company, the nuclear plant's operator, has struggled to tackle the crisis since the seismic disaster crippled cooling systems at the plant, triggering multiple reactor meltdowns and radiation leaks.

Since gauges were installed or repaired earlier this month, TEPCO has confirmed experts' fears that fuel rods inside reactors one, two and three have been exposed to the air and partially melted.

TEPCO now believes it will be impossible to end the crisis by the end of the year as it earlier predicted, Kyodo News reported today, quoting a senior company official who said "there will be a major delay to work".

TEPCO on April 17 announced its roadmap toward achieving a stable state of "cold shutdown" in all reactors in six to nine months. The company said earlier this month that it was on schedule.