Effects of food import tax
good news for farmers, not so good for shoppers
* UK farmers will become richer and thus pay more taxes, so the rest of us will need to pay less tax to 'balance the books'.
* Import tax also means less tax needed.
So at first glance it is good for tax payers, but the benefit will be felt most by the richer who will gain most by any tax cuts (assuming that this happens). Alternatively UK government could spend the extra tax receipts on helping the less well off - cushion them from price hikes.
But: it is all too complicated, and exposed to political whimsy, for anyone to predict with any accuracy.