John Lewis Partnership, which owns Waitrose, clocked up a 9th place overall, while Tesco lagged the field in 28th position.
The award was made by Business in the Community, which measures companies‘ impact on their staff, the communities they serve and on the environment.
Stephen Nelson, Sainsbury‘s marketing director, says: “This is a tremendous achievement for Sainsbury‘s, and is a further testament to Sainsbury‘s commitment to corporate responsibility.”
A spokesman for BITC explained that the results were taken very seriously, and formed a key benchmarking tool for ethical investors.
But he admitted that entrants were allowed to nominate the areas they wanted to be judged on.
Robust review and a 15% rate of checking each year made sure that the index was more than just a public relations exercise, he added.
Meanwhile, Sainsbury‘s is still locked in talks with a handful of small suppliers who objected to sweeping changes that would have extended payment terms to up to two months.
The supermarket has also revealed like-for-like sales growth of 5.4% (excluding petrol) in the 11 weeks to mid-March, reversing recent declines.