Leading article: Variety on the high street

So Tesco does not always get its own way after all. Barnet council's rejection of a planning application to open a small convenience store in north London is, of course, little more than a minor inconvenience for the supermarket leviathan in the grand scheme of things. But the decision is significant because it reflects a growing concern about what is happening to the high street as a result of the rapid expansion of the large supermarket chains. If other councils follow Barnet's example, Tesco may find it has reached the limits of its expansion in this area.

Barnet refused to permit the opening of a Tesco Express store in Finchley on the grounds that it would damage other local businesses. This comes as an increasing number of people are worried about the slow death of independent traders as a result of the incursions of supermarket giants.

It is quite true that small stores are closing at the rate of 2,000 a year, and much of this is a result of the new generation of convenience outlets being opened by the likes of Tesco, Sainsbury's and Marks & Spencer. But we should be careful about the conclusions we draw from this. In recent years, Tesco has bought up hundreds of small convenience stores from chains such as Europa Foods and Cullens. These were hardly quaint little local stores. In many cases, Tesco now provides a better service, more efficiently. There is no reason why it should be discriminated against on name alone. A blind upsurge in town hall protectionism would be wrong.

But there are, nevertheless, legitimate concerns about Tesco's dominant market position. One in every eight pounds now spent by the British shopper goes to Tesco. That gives the company great power, which could potentially be used to distort markets. We should remember that Tesco's concern is to boost its profits rather than guarantee the "vitality" of high streets. This raises questions of provision. Fresh food deserts in deprived areas are a growing problem. Local councils are right to consider this sort of thing when considering planning applications.

The demise of local shops and services is also a proper cause for concern. The springing up of "clone towns" with identical shops, restaurants and bars is indeed a dispiriting trend. And the expansion of supermarket chains into the high street undoubtedly contributes to it. Again, councils are right to acknowledge the economic benefits of maintaining a distinctive town centre. This is an area of controversy that will continue to grow as more disputed planning applications arise. The tricky job for councils will be to preserve a distinctive local community, while still allowing the market to decide which shops thrive.