Britain could launch military retaliation such as air strikes against a future cyber attack, the Defence Secretary has suggested.

Sir Michael Fallon warned potential attackers that a strike on UK systems “could invite a response from any domain - air, land, sea or cyberspace".

The Defence Secretary said the UK's ability to carry out its own cyber attacks against Islamic State in Iraq and Levant (Isil), also known as Daesh, had saved lives during the battle for Mosul in Iraq and the capability was also being used in the fight for Raqqa in Syria.