Nfu president Peter Kendall yesterday expressed his dismay at ASDA after the supermarket giant proclaimed its long term commitment to cheap food with full page advertisements in the national press.
In a letter to The Times, Mr Kendall said the tactic would be hard for farmers at the sharp end of food production to stomach.
Mr Kendall said: "While supermarket giants have been engaged in chest beating over cheap prices to the consumer they have been making very large profits. They have made those profits and kept their prices down by squeezing suppliers' margins to the point where many of them have gone out of business - one notable example is the 15,000 dairy farmers that have left the industry since 1996.
"As producers we truly understand that consumers need high quality food at best value but everyone should consider the issue of sustainability.
"If British farmers become so compromised by chokingly low prices they will find other ways to earn a living. More food will have to be imported from abroad with lower welfare and environmental standards and, in most cases, a larger carbon footprint. Will supermarkets be taking out full page adverts to boast about that?"