Leading article: Power and responsibility

The influence of the major supermarket chains on our lives is coming under unprecedented scrutiny. While millions take advantage of their low prices and the sector is applauded in the City for its efficiency, supermarkets are also accused of forcing independent grocers to close down and encouraging shoppers to drive to out-of-town superstores. It makes for an edgy relationship, as vividly illustrated by The Independent's recent campaign against waste, and the surprisingly intense public irritation with some supermarket practices which it uncovered.

But this is to focus on what we might term the downstream effects of the supermarkets' power - where they come into contact with consumers. The upstream effects, and in particular the ways in which they interact with their suppliers, are far less visible to the public at large, yet just as wide-ranging, and have just as big a potential for good or harm.

They were thrown into sharp relief yesterday when the president of the National Farmers' Union, Peter Kendall, accused the major supermarket chains of failing to give some suppliers, in particular dairy farmers, a living wage for their product, to the extent that three British dairy farmers a day were going out of business. We are used to NFU presidents asking for more money for their members; that's what unions do.

But there are two reasons why Sainsbury's et al should heed Mr Kendall's plea. The first is that there is independent evidence to back him up: 10 days ago the House of Commons All-Party Group on Dairy Farming found that while the retail price of milk had risen by 11 per cent in the past 15 years, the price paid to farmers for it had fallen by 10 per cent. The dairy industry was indeed being "ripped off" by the supermarkets, the MPs concluded.

The second is more fundamental: it concerns the effects of the supermarkets' vast buying power on the environment. We have seen this put to good use in their growing support for organic farming, allowing consumer preference for a more sustainable agriculture to be realised.

But driving small dairy farms to the wall, for the sake of a few pence off the cost of a pint of milk, cannot represent a healthy way forward for a patchwork, intimate countryside. Vast agribusiness operations and their industrial-scale operations have nearly always proved harmful to wildlife and the environment in general.

We are now realising that the supermarkets have the power to do to the countryside what they have done to many a high street; they should start to think hard about this power, and the responsibility it entails.