Tesco is winning the battle of the big three multiples when it comes to seizing the ethical high ground - and is even considered more ethical than Oxfam - according to a consumer survey.

The grocery giant comes in at eighth in a list of the UK's top ethical brands, compiled by researcher GfK NOP, ahead of Sainsbury's at number 10 and Asda at 14.

Waitrose, which trumpets itself as an ethical retailer, only ranks at number 12, while Morrisons is at 39.

All of them are behind The Co-op, which consumers voted the UK's number one ethical brand, and M&S, which ranked third.

GfK NOP quizzed 1,000 consumers. It showed them the various factors that could be used to define an ethical brand and asked them to name brands spontaneously that they felt met these criteria, which included fair trade, environmental friendliness, fair treatment of employees and donations to charity. "It is reassuring to know that the wide-ranging policies and developments we continue to implement are completely aligned with our being a consumer champion in ethics," said Martin Beaumont, group chief executive of the Co-operative Group.

Chris Davis, MD brand strategy for Gfk NOP, said: "Companies' business practices are more transparent than ever before. With an intense media spotlight, companies really have nowhere to hide.

"The more astute brands such as the Co-op are being rewarded by customers for taking a proactive stance in adopting rigorous corporate social responsibility policies and ethical credentials."

n M&S is Britain's greenest and most ethical supermarket, according to a poll of 1,000 consumers conducted by Populus and published by The Times this week.