From the Independent I read...
"Farmers say the dairies have slashed their margins for supplying grocers. Marks & Spencer, Waitrose, Sainsbury's and Tesco pay a premium above the farmgate price. Others supermarkets pay premiums below the 30ppl it costs to produce milk."
And only yesterday the Co-op boasts of increasing their payments to all of 29ppl...
http://www.co-operative.coop/food/ethics/Ethical-trading/milk-supply-policy/
Luckily, there is a man named after a fish who has promised to bang some heads together.