The government will hold a fresh public consultation on nuclear power stations, after the High Court ruled the first exercise was "seriously flawed".
Mr Blair says nuclear power is needed to cut carbon emissions
Trade and Industry Secretary Alistair Darling said they would not appeal, and a new consultation and White Paper would be published by early May.
But he said the government still backed the case for new power stations.
A judge ruled that the government's decision to opt for new stations last year had been unlawful.
Greenpeace brought the case after accusing the government of reneging on its promise to carry out "the fullest consultation" before deciding about whether to build new power stations.
It said, and the judge agreed, that the consultation that was carried out in 2006 gave insufficient information about radioactive waste disposal and the costs involved. Greenpeace called the consultation a "sham".
The judge said the information given to consultees was "wholly insufficient for them to make an intelligent response".
He issued a quashing order last week - effectively stalling any plans to press ahead with a new generation of power stations, by ordering a new consultation process to begin.
Mr Darling said, in a written statement to MPs on Thursday, that the new consultation would be conducted "endeavouring to meet the court's requirements".
"It is now likely that the White Paper and the new consultation will be published in early May," he added.
"However, if it can be published before Easter, I will do so."
The government had been expected to publish its White Paper next month.
It says nuclear energy is important, so Britain does not become dependent on imported oil and gas, and to reduce carbon emissions.
Mr Darling said the new consultation would enable people to take "an informed view" of whether nuclear should be part of the UK's energy mix.
"This will enable the government to make a decision on nuclear, and on certain other issues arising from the White Paper, in the autumn."