Major cyber-attack on UK a matter of 'when, not if' – security chief

Exclusive: Ciaran Martin says Britain fortunate so far to avoid major, crippling attack

The head of the UK's National Cyber Security Centre has warned that a major cyber-attack on the UK is a matter of "when, not if", raising the prospect of devastating disruption to British elections and critical infrastructure.

In remarks underlining newly released figures showing the number of cyber-attacks on the UK in the last 15 months, Ciaran Martin said the UK had been fortunate to avoid a so-called category one (C1) attack, broadly defined as an attack that might cripple infrastructure such as energy supplies and the financial services sector.