Terence Blacker: The price of cheap milk is too high

One day, those wanting to tell the story of the past 50 years through one product have an obvious choice: milk. During the post-war years of "Drinka Pinta Milka Day", it represented health and regeneration. The milk bottle on the doorstep was part of local life, the milkman a symbol of comic British naughtiness, from Benny Hill's Ernie, who famously drove the fastest milk cart in the west, to the ever-randy hero of that soft-porn epic, Confessions of a Milkman.

Today, as dairy farmers demonstrate against yet another cut in the price they are paid for their product, milk represents a less happy reality. In 2012, it reminds us, the market will always be put before the environment, health and animal welfare. Realising that milk is a uniquely emotive brand, supermarkets have ruthlessly used it as a loss-leader. They have squeezed the giant processing dairies who in turn have passed on the pain to the farmers who were supplying them.

The result of this brutal approach has been disastrous. Over the past few years, the vast majority of Britain's dairy farmers have left the business or moved into another form of agriculture. From an already low base, 200 farms have gone out of business in 12 months.

If the supermarket chains and processors continue to wield their power in the same ruthless manner, the only way to produce milk at any kind of profit will lie in the creation of giant mega-dairies of the type which have caused environmental, health and planning problems in America. The effect on the fields and hedges of the countryside, both in terms of the way they are enjoyed by humans and on their effect on biodiversity, will be profound.

Unless something is done to prevent the loss of traditional dairy herds, milk will become the ultimate emblem of contemporary greed and the worship of convenience. The type of countryside which is to be celebrated in the opening ceremony of the London games will disappear, in some places to be replaced by vast, inhumane, industrial dairies. It is all a long way from Ernie.