"One-third of our electricity generating capacity could go off-line over the next 10 years ... so doing nothing is not an option," he told a news conference.

Over the next 12 weeks officials will tour the country asking the public, industry and lobby groups what sources of energy they think should be used to generate the nation's electricity for the rest of the century.

A panel of experts drawn from various government ministries including the treasury and departments of trade, environment and transport will by the middle of the year draw up a report recommending where new investment should be spent.

Johnson highlighted the disruption to gas supplies over the turn of the year when Russia briefly switched off its pipeline that runs to Europe through Ukraine. He said that by 2020 Britain could be importing 80 percent of its gas.

But Matthew Davis of the Worldwide Fund for Nature (WWF) dismissed the review as too hurried.

"It looks like a smokescreen for nuclear new build," he said. "They have chosen the statutory minimum period for consultation and that just doesn't give enough time for a thorough review."

Guy Thompson of lobby group the Green Alliance said the terms of the review appeared too narrow, focusing on meeting expected demand rather than enhancing energy efficiency and curbing demand.

"If this turns out to be an exercise in predict-and-provide then it will have failed as a means to develop a coherent future energy policy," he said. "New nuclear is simply not necessary. Renewables and energy efficiency can solve the problems."

2003 REPORT

The study comes barely two years after a government report in 2003 said there was no need to replace Britain's ageing nuclear power plants with a new generation.

The nuclear plants supply 20 percent of the country's electricity, while renewables supply less than 4 percent.

Johnson rejected the complaints and said the outcome of the study was by no means a foregone conclusion.

"There is an awful lot of information already out there. This is not a replacement for the 2003 energy review. It is an enhancement of it," he said.

He said the study would cover all aspects of electricity production from renewables like wind and waves to combined heat and power plants, coal, gas, oil and nuclear.

Prime Minister Tony Blair, who commissioned the new study, is believed to privately favour building a new generation of nuclear plants, although finance minister Gordon Brown is thought to have reservations about their true cost.