Marks and Spencer is once again putting its Plan A corporate responsibility platform centre stage, while Tesco has also raised its environmental profile recently. However, Ben Cooper writes, allegations by Greenpeace that both retailers, along with others, have been sourcing beef from deforested areas of Brazil underline how careful companies have to be when staking out the moral high ground.

This week, UK retailer Marks and Spencer launched a new marketing push behind its Plan A sustainability programme under the tagline 'Doing the right thing'. The campaign is a further example of how companies are using social and environmental platforms in their marketing.

Tellingly perhaps, the executive taking the lead in this week's launch was the retailer's marketing director, Steve Sharp, rather than its head of corporate responsibility. Sharp said that Plan A put the retailer "in a leading position when it comes to environment and ethical issues", which could be interpreted both as promoting M&S as environmental pioneer but also differentiating itself from competition.

To a degree, this is just semantics. Few would suggest M&S is 'doing the right thing' for the wrong reasons. In fact, the retailer has won plaudits from campaigners for its environmental work.

And even if companies look to squeeze every ounce of PR benefit out of their environmental initiatives, is that such a bad thing? Campaigners often say having companies competing with one another for who can be greener is actually beneficial, while corporations mobilising their significant marketing resources behind green issues can only help the environmental cause.

Also, it is something of a truism in the business world that no companies know their customers better than major supermarket chains. When M&S says it is doing this because it is what its customers want, one can assume this is the case. Palpable consumer demand for greener products and greener retailers should also be a fillip for environmental campaigners.

Terry LeahyM&S is not the only prominent high street name to have put environmental concerns in the spotlight of late. Earlier this month, Tesco CEO Terry Leahy, spoke at a conference in London organised by Policy Network in association with the Centre for the Study of Global Governance at the London School of Economics.

Among the other speakers were UK Business Secretary Lord Mandelson; Matthias Machnig, State Secretary of the German Federal Ministry for the Environment; Greg Clark, UK Shadow Secretary of State for Energy & Climate Change; and Tony Blair. Choosing to speak at such an event underlines the high profile that Tesco is giving to its environmental agenda.

Interestingly, Sir Terry also focused on what Tesco was learning from its consumers. Describing consumers as "agents of change", he said the retailer was "helping consumers make green choices", for example by putting carbon labels on over 100 products. In the speech, he announced the retailer was also going to put carbon labels on its plastic bags, milk, bread, paper and home insulation service, and build a zero-carbon store in Ramsey, Cambridgeshire. "We've learnt a great deal about how we can reduce emissions and costs and about how we can influence customer behaviour," he said.

Collaboration between government, business and consumers was vital, Sir Terry added. Moreover, the speech underlined that it is in that close relationship with consumers, the insights and opportunities for influencing behaviour that it offers, that a company like Tesco can make a significant contribution, bringing something that the other stakeholders cannot provide. "Our aim is not simply to 'green' Tesco, but to spark the creation of something much bigger - a mass movement in green consumption," he said

Nevertheless, assuming a high profile in the environmental debate can carry risks, something that was brought home to UK food retailers earlier this month when Greenpeace published a report linking all the major UK supermarket chains with beef sourced from farms implicated in deforestation.

Greenpeace investigated three Brazilian beef producers, Bertin, JBS and Marfrig, which together account for around a third of Brazilian beef exports. While the UK retailers claim that their products are not made from beef from deforested land, Greenpeace asserts that the nature of the supply chains makes such claims difficult to verify. "In effect, criminal or 'dirty' supplies of cattle are 'laundered' through the supply chain," the campaign group says.

"While the blue chip companies behind reputable global brands appear to believe that Amazon sources are excluded from their products, Greenpeace investigations expose for the first time how their blind consumption of raw materials fuels deforestation and climate change," the report states.

Both Tesco and M&S were adamant that the checks in place ensured that the beef they bought was only from legitimate sources.

Speaking to just-food, M&S head of corporate responsibility Mike Barry said the company was "very disappointed" to be implicated in the Greenpeace allegations. He said the retailer had been working with Greenpeace for nine months to explain the verification and audit systems it had in place for beef.

"I think M&S has demonstrated to Greenpeace that we have full traceability in place," Barry said. "We have a good relationship with Greenpeace. What they do is very important but in this specific case they didn't get it right. We are absolutely confident in the traceability of our beef."

Sainsbury's was a little more guarded. A spokesperson for the retailer said: "We do use a small amount of Brazilian beef in our canned range. This represents 0.04% of the beef sold by Sainsbury's. We will continue to work with our suppliers to make sure that they are not sourcing beef from areas that have suffered from deforestation."

Morrisons said its suppliers provided documentation certifying that the beef they were sourcing was not linked to Amazon deforestation, while Asda also said it was confident that its Brazilian beef did come from the Amazon region.

Tesco said: "We have investigated the claims and received written assurances from our suppliers named in the Greenpeace report that they have strong systems in place to ensure beef products do not originate in the Amazon area. Additionally, we have an ongoing independent auditing programme which will highlight any future issues. If any supplier is found not to comply with the law or our policies, which prohibit the sourcing of products from the Amazon area, we will not hesitate to delist them."

However, a Tesco spokesperson told just-food it would be "very hard" to ensure that a supplier was not sourcing beef from the Amazon and supplying it to someone else, and would potentially involve auditing factories and supply chains that the retailer was not involved with.

The recent Greenpeace findings underline how complex supply chains can often make social and environmental undertakings hazardous, as the clothing and footwear industries can attest.

In this instance, the media attention was not huge and has been relatively short-lived. But the issue will not go away. Monitoring suppliers, auditing, checking and double-checking are clearly vital in underpinning corporate social responsibility aims, and the more publicity a company gives to its social and environmental agenda the higher the stakes if it slips up.