Question to the Ministry of Defence:

To ask the Secretary of State for Defence, what assessment he has made of the threat posed to the Trident nuclear weapon system by cyber-attacks; and what steps he is taking to ensure that system is secure against such attacks.

The Ministry of Defence audits the integrity of the UK's nuclear deterrent regularly for all threats and hazards and acts to ensure that it maintains the highest possible standards. The Strategic Defence and Security Review acknowledges the growing cyber threat and the importance of investing in cyber security across all of our capabilities. The Government has invested £860 million in new technology and capabilities since 2011 and will invest £1.9 billion over the next five years in protecting the UK from cyber attack and developing our sovereign capabilities in cyberspace. Our approach to protecting Defence capabilities against and mitigating the impact of cyber attacks spans technical, organisational, procedural and physical measures benefiting many different systems and networks, and investment is integrated across these measures. Submarines operate in isolation by design, and this contributes to their cyber resilience. I will not discuss further details for reasons of safeguarding national security.