Streeting is accused of scaremongering as Britons are told to stockpile three days of food and water for a crisis

Defence Secretary Wes Streeting told families to be 'alert but not alarmed' while dismissing the charge. The 'Be Ready' checklist advises nine litres of water per person, tinned food, cash and a wind-up radio. Ministers stand accused of lecturing families while refusing to spend more on defence. The guidance went live just as 32 government websites went dark over a PHP security flaw.

'How would we cope if the payment systems at the local supermarket went down?' Streeting asked.

David Miliband backed the call, warning the 'drums of war are beating louder'.

A government study found only 13% of people feel prepared for a major blackout.