[JohnW]

I'm an accountant who used to be employed by a large farming company who grew and packed fresh produce for various supermarkets. The supermarkets have been screwing them into the ground for years. They will go abroad to get cheap imports rather than pay a little more for 1st. class fresh British produce. So, they threaten the British farmer with that, and if he wishes to sell to them he has to do so at their price, often at a loss.