Joan Smith: How to shock shoppers out of their wilful ignorance

I wasn't out of the country for long. But while I've been in Jordan, dodging the President of France and his new girlfriend, it seems that people at home have been getting terribly upset about chickens – battery chickens, that is, whose short, miserable lives have been exposed by a celebrity chef. Now, I don't have any quarrel with Hugh Fearnley-Whittingstall, a decent bloke who was moved to tears by the dreadful condition of the hens in his three-part series this week for Channel 4. But I can't help being dismayed by the fact that it takes a TV chef to turn animal welfare into something people care about.

Intensive farming, driven by relentless supermarket demands for ever-cheaper food, has been responsible for dreadful conditions in the industry for many years. It's tempting to think of it as a class issue, in which poor people who live on council states have become so detached from the origins of food that they don't think about the circumstances in which battery chickens are reared. There may be some truth in that – Mr Fearnley-Whittingstall's series set out with the laudable aim of changing people's unthinking habits – but it's only half the story.

It isn't just working-class people who scour supermarkets for special offers, packing their freezers with industrial quantities of cheap meat from animals which certainly weren't reared in the open by organic farmers who care deeply about their welfare. The problem lies in the widespread assumption that low prices are a consumer right, an idea we've got so used to that people are affronted by the suggestion that they should pay more for food or clothes.

When the big Primark store opened in London's West End, I had identical conversations with half a dozen friends who returned with bags stuffed with cheap clothes. "This was only £10!" they exclaimed, holding up a top or a pair of jeans, and it turned out that none of them had given a moment's thought to how these incredible prices had been achieved. The answer falls into the category of the absolutely bleeding obvious, which is that big chains such as Primark, Tesco and George at Asda source their clothes from factories in developing countries where the mostly female workforce puts in incredibly long hours for scandalously low rates of pay.

These women aren't quite the human equivalents of battery chickens, but their plight has exactly the same cause. Last year War on Want reported that Tesco's stores were being supplied with clothes made by 25,000 garment workers in Bangladesh whose average salary was around £15 a month. It also pointed out that a worker making clothes in Mauritius for Sir Philip Green's Arcadia group would have to work for almost 4,000 years to earn the £3m paid to Kate Moss for her Topshop clothing range.

All this information, whether it's about human or animal misery, is easily available to anyone who cares to look for it. But consumers have been targeted for years by aggressive advertising campaigns promoting three-for-the-price-of-two offers and the perverse notion that shopping is about saving money. They've come to think that price is all that matters, even if the result – clothes which fall apart in months, meat stuffed with antibiotics and growth-promoters – is shoddy or tasteless. In the old days, this would have been just the kind of scandal that propelled people into politics, fired up by a vision of a better world. Now demand is everything, quality and morality have gone out of the window, and it's left to the occasional celebrity with a conscience to jerk people out of the willed ignorance which informs their shopping habits.

I find this genuinely shocking, especially after a decade in which the country was led by a prime minister who made a virtue of confronting difficult moral choices. Tony Blair gave us the Iraq war and faith schools, where children are taught the limited moral agenda which suits the Vatican or Islam, but didn't even attempt to start a national debate about the ethics of consumerism. There is an opportunity here for Gordon Brown, if he's prepared to grasp it, and the Government should start with a simple but dramatic measure.

In the organic meat section of some supermarkets, it's quite usual to find labels featuring a smiling farmer and details of the conditions in which his or her animals are reared. Ministers should make it compulsory to display photographs of all the farms whose meat is on the shelves, along with a description of the animals' diet and living space. The same principle should apply to clothing chains, which would be obliged to provide pictures of the factories in which their garments are made and list what the workers are paid per hour. Ethical shopping is too important an issue to be left to TV chefs.