Chancellor George Osborne has announced that the UK will guarantee a £2bn deal under which China will invest in the Hinkley Point nuclear power station.
Mr Osborne, who is in China, said the deal would pave the way for a final investment decision on the delayed project by French energy company EDF.
He said it would also enable greater collaboration between Britain and China on the construction of nuclear plants.
Reports suggest one such reactor could be built at Bradwell in Essex.
The new power station would be Britain’s first new nuclear plant for 20 years and is expected to provide power for about 60 years.
Speaking in Beijing at a joint news conference with China’s Vice-Premier Ma Kai, Mr Osborne said: “We want the UK to be China’s best partner in the West. [This guarantee] paves the way for Chinese investment in UK nuclear [to help provide] secure, reliable, low carbon electricity for decades to come.”
He also announced a new £50m joint research centre for nuclear energy.