Critics say Prime Minister Yoshihiko Noda, whose top priority is raising the sales tax to curb bulging public debt, is caving in to Japan's "nuclear village" - a powerful nexus of utilities, bureaucrats and businesses - by restarting the first of Japan's 50 reactors to come back on line since the crisis.

Kansai Electric Power Co's No. 3 unit at its Ohi plant, in western Japan, will resume supplying power to the grid as early as Thursday, and its No. 4 unit will also restart this month, as the government seeks to avoid a summer power crunch.

Many experts, though, say the nuclear interests are unlikely to win the longer-term battle given the hidden costs of atomic power exposed by Fukushima and a new set of forces pushing for a bigger role for renewable sources of energy such as solar power.