Environment group Greenpeace on Thursday began a legal challenge to the British government's bid to push ahead with a new nuclear power programm.
The government said in its energy review in July it was vital to renew the country's ageing nuclear power stations both to combat global warming from burning fossil fuels and to reduce rising dependence on imported energy supplies.
But environmentalists reject nuclear power as too expensive and too dangerous, and on Thursday Greenpeace, citing numerous supporting statements, set out to prove the process by which the government arrived at its conclusions was flawed.
No comment was immediately available on Thursday from the Department of Trade and Industry which ran the review.
At the outset of what they hope will result in a full judicial review, Greenpeace lodged papers with the High Court in London arguing that the government ignored adverse advice and failed to carry out a full public consultation.
"A judge must now decide whether to give us leave for a judicial review," a spokeswoman said. "If the decision is positive then we could be looking at early next year for it to begin."
"At the very least that should put the brakes on the government's rush to clear the way for new nuclear plants."
If they are ultimately successful, the government will be forced to put aside its conclusions and go back over the review process which, although dubbed a public consultation actually gave the public little opportunity to hear the arguments.
But time is short.
Nuclear power plants supply some 20 percent of Britain's electricity, but most of the elderly plants are due to close within a decade and the last one is set for closure by 2025.
In the past, public planning enquiries about plans to build nuclear power stations have taken years.
In a bid to shorten the process, the government is considering pre-approval of nuclear power plant designs and limiting the scope of public inquiries to purely local issues.