Around 30,000 jobs may be created and a £60bn boost to the economy generated because of a UK-France nuclear energy deal agreed by the two countries' leaders.
Prime Minister David Cameron and his French counterpart, President Nicolas Sarkozy, are signing a declaration in Paris that will see an initial £500m of deals between French and British companies.
This will mean a new generation of nuclear power plants being built on British soil at sites in Somerset, Suffolk, Cumbria, North Wales and Gloucestershire, which will eventually generate billions of pounds for Britain.
While the potential for 30,000 new jobs will take time to come to fruition, 1,500 jobs will immediately be created as work starts on new facilities off the back of the deal.
Rolls-Royce and French energy company Areva reached a £400m deal that will see a new factory built in Rotherham, South Yorkshire, to supply services to the first new nuclear reactor to be built by French energy giant EDF at Somerset's Hinkley Point.
"I want the vast majority of the content of our new nuclear plants to be constructed, manufactured and engineered by British companies," Cameron said.
"And we will choose the partners and technologies to maximise the economic benefits to the UK. Today marks an important first step towards that - a good deal for Britain and a good deal for France."
Ed Davey, Britain's energy secretary, was also travelling with Cameron to Paris.
"We need hundreds of billions of pounds of investment in clean energy projects in the UK. This will bring high-skilled job opportunities the length and breadth of the country," Davey said.
Anti-nuclear campaigners hit out at the agreement.
"No amount of talking up of the French nuclear industry by David Cameron and Nicolas Sarcozy will cover up the fact that the economics of new nuclear reactors don't stack up," Dr Doug Parr from Greenpeace said.
"The track record of EDF in building new nuclear power stations on time and to budget is appalling.
"Recently the independent risk agency Standard & Poor's downgraded EDF's creditworthiness. French nuclear power is no longer popular even in France.
"So instead of using UK taxpayers' money to prop up failing French industries, David Cameron should follow the lead of Germany and concentrate on securing vast numbers of jobs and economic growth in the rapidly expanding clean energy industries such as wind and solar power."