I’m not an economist: take whatever I write with a barrel of salt.
The unemployment rate in the UK, like in many other countries, has been going up. There are indications that underemployment is also becoming more prevalent, where working hours are cut. Naturally the situation is more dire and more serious for those who have lost their jobs completely, but being underemployed also makes life difficult, since fewer hours worked means less disposable income. I believe Britain, if pressed, can feed its own population, even if that means potato, cabbage, turnip and bits of beef and mutton in one form or another, meal after meal, day after day. So, even if the currency goes to the dogs and Britons cannot purchase any imported food, there will be no mass starvation. However it remains true, that with the falling value of GBP, imports will become more expensive, both raw materials used for manufacturing and as finished products. So deflation may occur in selective products, but perhaps not on necessities, and many more Britons will be worrying about how best to spend the less money that they still have.