British spies will scrutinise computer systems and cybersecurity at nuclear plants built by Chinese companies, amid fears that Beijing could use new commercial deals to threaten the UK’s national security.

The role of the listening station GCHQ in protecting Britain’s energy network from cyberattack has been confirmed as President Xi lands in London tonight on a four-day state visit hailed by David Cameron as the start of a “golden era” in Britain’s relationship with Beijing.

The Times disclosed last week that security chiefs had expressed concerns to ministers about the decision to ask Chinese companies with links to the military establishment in Beijing to take a stake in three nuclear power plants.

Negotiations over China’s role in the first project, at Hinkley Point, Somerset, continued