Technological suggestion

[Mortblanc]

You are probably correct about the effect on the average middle class English family, they are all going to die, but what about the others.

1/4 of the population of GB was born outside the Island. They came to you from Pakistan, India, Africa, the West Indies, Romania and points east. They grew up in mud huts and slums and 3rd world conditions and they know how to survive in places where no one has ever seen a light switch or had a solid bowel movement.

They will be cooking on campfires built in tin pots on their window stills within 24 hours.

And when the food runs out they will be the first ones to start walking.