When Wal-Mart starts selling a line of organic cotton baby clothes in Europe and Japan later this year, the new products will account for just a fraction of its annual sales of about $300bn.

But Wal-Mart’s embrace of organic products underlines the question now facing environmental activists and others who have pressed the company to change its business practices: is the world’s largest retailer setting off after Nike, Gap and others to embrace the cause of good corporate citizenship?