A company backed by Jeff Bezos, the Amazon founder, is to build its first nuclear fusion plant in the UK in a bid to show how the technology can be turned into a realistic source of clean energy.

General Fusion, a Canadian start-up that wants “to transform the global energy system”, will build the large-scale plant at Culham in Oxfordshire, which is already home to a fusion research programme run by the UK Atomic Energy Authority (UKAEA).

General Fusion said it had signed an agreement with UKAEA under which it will build and operate its fusion demonstration plant at UKAEA’s Culham campus. General Fusion will enter into a long-term lease with UKAEA following construction of a new facility at Culham to host the new plant.

The development, said to cost about $400m (£232.5m), will be subsidised by British taxpayers, though the government has not said how much it is putting in.