We've had Sainsbury's plastic packaging plan; Tesco's carrier bags scheme; The Co-operative Group's switch to green electricity; Asda's direct to store delivery scheme in Cornwall; Waitrose's "best supermarket" Soil Association awards; and Marks and Spencer's Look behind the Label campaign. The list goes on. But who is the greenest of them all and are they prioritising the right areas ?

The results of two recent surveys paint a mixed picture. Consumers think Tesco and the Co-ops are doing the most on the environmental and ethical fronts, according to a survey by Harris Interactive. However, the National Consumer Council Greening Supermarkets survey, which tested the top eight supermarkets on four key green indicators, places Waitrose in the top spot with a B rating, gives Sainsbury's and Marks and Spencer's Cs; and Tesco, Asda and the Co-ops lowly Ds.

The disparity between the two verdicts shows how important a strong brand and a bit of good PR can be in influencing consumer attitudes. In the last Harris Interactive survey, in June, consumers rated the Co-ops top in both arenas - partly because consumers see the brand as synonymous with ethical issues.

Tesco was second on both, but has since nicked the top spot on the environmental front in the wake of good PR surrounding campaigns such as its bag initiative and its community plan. Waitrose, on the other hand, which with Marks and Spencer and the Co-ops are seen as ethical and environmental pioneers, comes third on both scores.

The Harris survey suggests that consumers are not interested in who got the ball rolling - Tesco is after all a relative newcomer to all things green. But whether you take its or the NCC's verdict on who's the greenest, all the multiples are now being judged on their green credentials, regardless of how much substance there is to their initiatives.

One area where there is clearly synergy between customer expectations and retailer aspirations is recycling and waste.

Caterina Gerlotto, senior researcher at Harris Interactive, says: "Recycling appears to be central to supermarket selection. It seems that the recent bag campaign by Tesco has made an impact. However, ultimately, the strongest driver is not ethical or environmental, but financial."

Even so, the multiples are raising their games in both arenas. Why? Because customers, investors and the media want them to and it allows them to save money while adopting the moral high ground.

Mark Shayler, environment director at Environmental Capital and MD of Eco3, says: "There is a whole raft of drivers. When the pressure groups were banging on about it, that was not enough to create a tipping point. When you get customers beginning to ask questions, then investors, then the policymakers, you've got a lot of people who are concerned. That's when you've got a tipping point."

Mike Barry, head of CSR at M&S, which consumers rank a surprisingly low fifth and fourth on environmental and ethical issues respectively in the Harris survey, agrees that consumers have been a major driving force: "What we saw at the turn of this decade was a beginning of a shift in consumer interest.

"They were saying: 'We don't just want you to give money to charity.' They started to ask more questions, but at the same time said: 'Don't bore us with the details'."

Alison Austin, head of brand policy and sustainability at Sainsbury's, agrees. "It's certainly not PR spin. Customers are really interested in the whole issue of where food comes from and what impact it's having on the environment."

That's why there's been such an explosion of interest in fair trade, organic and more locally sourced products, she says. Despite all the customer-focusing initiatives, the experts reckon supermarkets are targeting the right areas.

They're certainly ticking lots of boxes on the environmental and recycling front. Robin Maynard, campaigns director at the Soil Association, says they're also responding proactively in areas such as organic. Of Tesco and Sainsbury's launch of box schemes, he says: "Yes, they're using the opportunity of the high profile of organic but they wouldn't be doing it if they weren't pressured by customers." Meanwhile, the NCC said that supermarkets needed to improve in a number of areas including recycling and sourcing of seasonal UK fresh produce.

These actions then need to be more effectively communicated, says Sue Dibb, principal policy advocate and the report's author: "The main surprise was how little the retailers were actually using their environment to communicate with customers about green issues.

"Yet green issues are going to be as strong as health issues in a relatively short period of time."

The multiples still need to address the way they treat suppliers, says Vicki Hird, campaigner at Friends of the Earth: "Prices paid to suppliers continue to be driven down. None of what they're doing is happening fast enough to tackle problems such as climate change and worker conditions.

"A lot has happened, certainly in energy, but we have to look at the real problem. That's why we've been clamouring for the supermarket code of practice to be strengthened."

Time will tell whether the multiples' race to be the first with the latest green initiative will take them beyond easy environmental wins into the tougher terrain of supplier relations.