Ethically sourced products, such as fair trade, free range and organic lines, have grown rapidly in recent years. The Co-operative Bank reported that the ethical food market topped £4bn for the first time last year.

There have been some notable introductions of fair trade products by wholesalers of late. Booker last month became the first cash and carry to offer an exclusive range of fair trade wines, while Brakes launched an own-label coffee, a first in foodservice. But what is the broader potential for ethical products in wholesale?

A poll of our reader panel, which comprises key figures in the wholesale industry, indicates that they all offer some ethically sourced products. The most common such products are fresh organic produce and fair trade coffee.

However, penetration remains very low. None of the panel generates more than 10% of their turnover from ethically sourced products and most have numbers well below 5%.

Several wholesalers put this down to the fact that consumers are simply not demanding the products.

One exception mentioned by several members is coffee. This has had the benefit of a long-running consumer awareness campaign backed by the Fairtrade Foundation, which has driven consumer demand. A panel member says: "We do well with fair trade coffee, because consumers know about it and want it."

That said, the panel indicates that wholesalers are moving to expand their offers: 71% of them said that they plan to increase the number of ethically sourced products that they list within the next 12 months.

This optimism is limited, though, as only 43% of the panel believe that there are significant untapped opportunities for ethically sourced products in the wholesale channel.

Several panel members who say that there are opportunities suggest that the key to success will in fact be links to local provenance.

One member from the south notes: "Consumers do have a strong desire for local products, so if, for instance, you do organic products in the wholesale market, you have to make sure that the end consumer knows that they come from the local area. That does drive sales."