The government will announce on Thursday whether it will give the go-ahead to a new generation of nuclear power stations, Gordon Brown's spokesman said on Monday.
The government is expected to approve the programme, sparking a fresh challenge from environmental campaigners.
Business Secretary John Hutton's announcement on energy policy, expected to be made in a statement to parliament, will include "the decision on whether or not to go ahead with the next generation of nuclear power stations", the Prime Minister's spokesman said.
Asked about a report in the Guardian on Monday that consumers may face higher electricity bills to cover the future decommissioning costs of new nuclear power stations, Brown's spokesman said plant owners would have to foot the bill.
"If the government decides that new nuclear should be an option, owners and operators of new nuclear power stations would have to set aside funds to cover the full costs of decommissioning and their full share of the costs of the long-term management and disposal of waste," he told reporters.
In a New Year's message last week, Brown gave a strong hint that his government will approve new nuclear plants when he pledged to "take the difficult decisions on energy security", including on nuclear power.
Nuclear operators say they could have new UK plants running by 2017, helping Britain to meet its 2020 goals for fighting climate change.
Last February a High Court judge overturned the government's initial go-ahead, saying it had failed to consult the public properly.
Environmental group Greenpeace says a decision in favour of nuclear this week would still be unlawful, largely because people were given flawed information in the second consultation and because there is still no plan for radioactive waste.
