Dr Paul Dorfman, an Honorary Senior Research Fellow at the Energy Institute, University College London, said EDF, a majority French-owned company, is 'extremely unlikely' to invest given the current economic climate.
The long-delayed project was due to have Hinkley Point power station producing 7 per cent of the UK's electricity by 2017. But, if built, the earliest date it could now start doing so is 2025.
Even that looks a remote possibility according to Dr Dorfman, who told MailOnline Brexit was 'the final nail in the coffin' for Hinkley Point.
He said: 'It gives everybody the chance to slip out without losing any more face.
'How is France going to invest in the UK if the UK is no longer part of the union?
'Not only that but the French nuclear industry has huge financial problems and unions are screaming that they don't want it [Hinkley Point].'