Wes Streeting with Gen Sir Roly Walker at the opening on Thursday of a Rheinmetall factory in Telford, West Midlands.Photograph: Christopher Thomond/The Guardian

Every Briton is being urged to stock up to nine litres of bottled water and three days' worth of food in new government guidance designed to ensure that households can survive a weather, cyber or other serious emergency.

The Be Ready campaign is aimed at persuading people to stock up with supplies to last 72 hours, amid growing official concern about the impact of the climate crisis, technological dependency and hostile state threats.