The future of the UK nuclear industry has been put at risk by the Government's failure to consider the "serious ramifications" of its Brexit strategy, MPs have warned.
The influential Business, Energy and Industrial Strategy Committee raised concerns that the EU divorce could distract ministers from delivering important climate change policies and throw the industry into flux by removing key standards.
In a new report, the cross-party group of MPs said there was a long-term risk the UK could become a 'rule taker', where it was unable to influence the European rules and standards it had to comply with.
Labour MP and committee chairman Iain Wright said: "The Government has failed to consider the potentially severe ramifications of its Brexit objectives for the nuclear industry.
"Ministers must act as urgently as possible. The repercussions of failing to do so are huge. The continued operations of the UK nuclear industry are at risk."
Plans to leave the nuclear research agency Euratom had been poorly thought out, as delays to finding an alternative could threaten power supplies and inhibit nuclear trade and research, the report said.
The committee urged ministers to find transitional arrangements to keep Britain in the agency until a new plan could be hammered out.
Mr Wright said: "The Prime Minister has made it politically unfeasible to remain in Euratom long term.
"The Government now has a responsibility to end the uncertainty hanging over the industry and ensure robust and stable arrangements to protect trade, boost research and development, and ensure safeguarding of the highest level."
Other recommendations included maintaining access to the EU's Internal Energy Market and staying as a member of the Emissions Trading System until at least 2020.
Mr Wright added: "In the short term, the Government should seek to avoid disruption to the energy sector and domestic climate change agenda.
"Government needs to provide as much clarity and stability as possible to support investment and avoid damaging UK competitiveness and adversely affecting consumers."
Justin Bowden, national officer of GMB union, said: "The latest stark warning about Euratom and the Brexit approach to nuclear power, yet again emphasises our Government's lack of anything that could be called a coherent energy policy.
"Nuclear, particularly new nuclear, and the zero carbon power it produces, is crucial to the UK's future energy needs.
"In a world outside of the European Union, energy self-sufficiency is common sense and nuclear, alongside gas, will be fundamental in that reliable mix.
"Decisive action must take place now. The electorate will not forgive politicians of any political party who fail in their duty to maintain the electricity supply."
Business Secretary Greg Clark said: "The future of the nuclear industry in this country can only be protected by a Prime Minister who will actually stand up for Britain and nuclear power in Brexit negotiations.
"That's the stark choice in this election - strong leadership with Theresa May, who has already commissioned the first new nuclear power station in a generation, or entrusting Britain's nuclear future to floundering Jeremy Corbyn, a man who has spent his political career pushing for nuclear power stations to be decommissioned entirely."