Theresa May delayed approving Britain’s first new nuclear power station in a generation amid security concerns about China’s involvement.

The Prime Minister told Francois Hollande, the French President, last week that she needed more time to make a final decision and reportedly questioned the role of Chinese companies involved in the deal.

Nick Timothy, Mrs May’s joint chief of staff, previously warned that the Chinese could use their role in the programme to “build weaknesses into computer systems which will allow them to shut down Britain’s energy production at will”.

Mr Timothy, in a blog post last year, said that MI5, which has been involved in discussions about Hinkley Point, had concerns over China, saying that the country's intelligence services "continue to work against UK interests at home and abroad".