The call comes as many dairy famers are once again being paid less for their milk than it costs to produce it. In a letter to all the major retailers, discounters and major food service players the NFU, Farmers for Action, Royal Association of British Dairy Farmers, Dairy Farmers of Scotland, NFUS, NFU Cymru and the Farmers' Union of Wales have called for action to increase confidence among dairy farmers to stop the erosion of critical mass within the sector.

The industry-wide group says that everyone in the milk supply chain needs to make a fair profit and calls for retailers to stop gambling with security of milk supply. The letter asks for three commitments from the industry's biggest customers:

* Commitment to sourcing British dairy products. 

* Transparent and stable pricing mechanisms for liquid milk and cheese suppliers that offer producers a sustainable milk price. 

* Promotion of the Red Tractor on all own label, British dairy products.

The letter states: "Our message is very simple. If you want to guarantee a supply of quality British milk, cheese and dairy products you must take steps to secure it."

NFU Dairy Board Chairman Gwyn Jones said: "As British milk supply continues to fall, consumers are increasingly denied the opportunity of choice they deserve to purchase British dairy products; products which are produced to the highest welfare and environmental standards in the world.

"Consumers are paying a fair price for British dairy products but that money is not distributed fairly down the supply chain. The difference between profit and loss for dairy farmers in this country is a small fraction of the overall margin on milk and dairy products, which could easily be afforded."