The recently compiled energy strategy aimed at phasing out nuclear power by the 2030s is likely to be revised under the next government, expected to be led by the Liberal Democratic Party, which has been critical of the push to completely abandon atomic energy despite the Fukushima No. 1 reactor meltdowns last year.

But the target date for the formation of a new medium- to long-term policy remains uncertain. In its election pledges, the LDP states that it plans to spend up to 10 years determining the best energy mix for the resource-poor country.

"The new government may prefer to take plenty of time to work out a new energy policy, saying something like 'We will think about whether it is appropriate or not to choose a zero-nuclear path,' " a senior government official familiar with energy issues said.