Leading article: The high cost of all this cheap clothing

The world's top designers are showing their latest collections in New York this week, with couture pieces priced at thousands of dollars. But within weeks, cheaper versions of the same trends will be available in high street shops the length and breadth of Britain. Never have the fashion-conscious had it so good, especially those who need to count their pennies.

The past five years have witnessed the arrival of "fast fashion" - the rapid progress of clothes from the catwalk to the shopping centre - and a constant turnover of products on the rails. We have also seen the rise of the cut-price clothes store: fashion magazines are now as likely to promote Primark and TK Maxx as they are Chanel and Burberry. This summer's must-have dress - worn by everyone from A-list stars to suburban teenagers - was a £10 polka-dot shift from Primark.

Dedicated followers of fashion will say these changes have democratised the industry, allowing anyone to buy the latest trends, regardless of their budget. And reasonably priced variety, in clothing as in so much else, is surely one of the great delights of the modern world. But this accessibility has an ugly side. The price of women's clothing may have fallen by one-third in the past decade, but most companies have been able to keep their costs down only by turning a blind eye to the execrable conditions in which these cheap clothes are often produced.

The ending of the Multi-Fibre Agreement last year transformed the industry overnight, when a free-trade system for garment manufacturing replaced a situation that had protected suppliers in countries such as India and Bangladesh. Thousands of companies relocated factories to China, drawn by the low wages and - while they may not have admitted it - an absence of labour rights that drove costs down even further.

As a result, wages in the "older" manufacturing countries have been further slashed in an effort to compete. Salaries for garment workers in Bangladesh, for instance, have been halved. Too many British - and other first-world - companies are hiding behind meaningless Corporate and Social Responsibility codes of conduct when the reality is that factory workers - mainly women - are being denied a living wage, the right to join a union and the protection of regular, independent inspections of their workplaces.

Such a vicious spiral, however, is not inevitable. The new cut-price fashion stores should look to the example of Gap to see why, far from jeopardising their bottom line, it would be in their interest to look more closely at the conditions in which their "instant" fashion garments are produced. Although Gap had rocketed to global fame, it had become associated more with the scandal of sweatshops than with the celebrities who endorsed it. Sales fell, as a new generation of more ethically aware customers saw the Gap logo as a badge of shame rather than honour. So the company changed its policies. It pushed its suppliers to pay their workers a living, rather than just the legal minimum, wage. And it worked with, rather than against, trades unions on collective bargaining and factory inspections. Gap's fortunes have now been revived - and the price of its clothes remains low. After all, the difference between the cost of labour - which is counted in a few pence - for a T-shirt that sells for £8, leaves a generous margin for adjusting workers' pay and still plenty left over for the intermediaries.

Ultimately, however, it is not only the clothes companies that must look to their consciences, but the fashion-following customers as well. We worry about whether our carrots are organic, our coffee free-trade and our furniture from ethically sourced wood. There is no excuse for not doing the same with our clothes.