>>TIM LANG, PROFESSOR OF FOOD POLICY, CITY UNIVERSITY, has worries about the future of fair trade and ethical lines

I pinched myself listening to Stuart Rose of Marks and Spencer launching Fairtrade Fortnight. Who would have thought even five years ago that middle England retailing would not only stock fair traded products but grow the range.
The figures are impressive - some 50% up on last year. There were announcements that not just Marks and Spencer but Topshop is going ethical. I have a feeling of arrival after years on the fringe.
I am always been moved hearing the difference it makes to growers' lives. I toasted the South African woman worker from the winery whose rosé we drank.
Moving around the packed Sadlers Wells foyer - as at last year's Foreign Office event - I mused less on how far the fair trade slice of retail action has come, as on the rocks that, unfortunately, lie ahead.
Yes, big questions loom.
At City University, we are finishing an EU study of ethical traceability of foods. It's amplified my worries. The issue is not whether one can be sure about genuine traceability when you buy the ethical socks Rose wore or the peanuts that we munched.
We can assume that sort of traceability is got right. Harriet Lamb's Fairtrade Foundation sees to that, not just M&S, The Co-operative Group, Sainsbury or Waitrose.
To the cynics - and some retail buffs are - the line is 'if these over-paid sandal-wearers want more expensive products, we'll sell them'. Ethical trading is admittedly just a niche. But it is a chance to incorporate ideas from some dissidents.
A movement that came out of third world solidarity (mostly socialist) and the hairy end of the churches has given a wonderful new product range. Saturated markets always need new shocks at the boundaries.
Eco-critics might ask at what point Western consumerism decides enough is enough. The cynics say: more, more, more! So from their point of view, ethics is just good for business.
But where are things heading? One nightmare scenario is fair trade suffering the fate of organics in the early 1990s. Quickly adopted, it was quickly dropped. Organic farming nearly went under.
Another nightmare is if the movement walks away from the product. As the ethical brand gets better recognition, it quietly severs links with its bedrock social movement. It becomes too slick. There were frissons in 2005 over Nestlé's minuscule fair trade coffee launch and Cadbury buying Green & Black's. Engaging with the enemy? Or growing up?
A structural problem is the plethora of 'labels' just within fair trade. There are many appeals to consume differently: organic, animal welfare, fair trade, fish conservation, forest conservation, heritage, localism, public health, quality, transparency, slow food, labour rights, anti-oppressive regimes, religion. The problem is joining them up. Should they merge? Wouldn't it be better to have one label, one movement?
This is where problems get serious. What is the movement? Take the crossover of health and fair trade. No questions about it, fair trade lifts people from poverty if not to wealth definitely to security. This is great for their health.
But, fair trade fan though I am, its product range does not necessarily pass the health laugh test. Sugar, alcohol, chocolate as big sellers? Hmm. Is long distance fair traded cotton less environmentally damaging than exploitative? Indirectly, yes, but you see the point. Vice versa, tropical fruit drinks are great for health (one a day) but poor for food miles.
The movements that gave birth to not just fair trade but all 'alternatives' each have great evidence that consuming their product helps. The problem is that when these products go mainstream, the appeal needs to go horizontal.
Sophisticated consumers already want products scoring not just on one ethical dimension but all of them. Contradictions loom. Not now, not next year, but soon, serious thinking is needed. Can we put that on a label?