Some of the latest milestones reached by retailer Marks & Spencer under its Plan A ethical programme include using sustainably sourced cotton in 900 products and saving 865 tonnes of clothing from going to landfill. 

The company, whose goal is to become the world's most sustainable major retailer by 2015, also says 35% of the products it sells - over a billion items a year - now have a Plan A eco or ethical attribute.

The aim is to raise this to 50% of products by 2015 and 100% by 2020. Items include knickers made in an eco factory and jeggings made with BCI cotton and dyed in an eco dyehouse.

Likewise, cotton sourced to Better Cotton Initiative (BCI) standards is now being used to make 900 M&S products, including some of its best selling lingerie and jeans. From June next year, all pure cotton and cotton rich school uniforms will use BCI cotton.

In total M&S says it has purchased 4,000 tonnes of BCI cotton in the past six months and intends to grow this to over 15,000 tonnes in the next three years.

BCI cotton is better for the environment as it is grown using less fertiliser, less water and fewer chemicals and earns more money for the farmer by reducing input costs and helping them manage crops better.

BCI cotton is an "important part of our sourcing mix now and we want it to grow and grow," explains M&S cotton expert Mark Sumner.

We've committed to source 25% of our cotton from more sustainable sources by 2015. We need BCI cotton alongside Fairtrade, Organic and recycled in our business so we can achieve this step change in environmentally conscious cotton sourcing."

A line of sustainable suits is also being re-introduced for spring/summer after an initial run of 500 sold out.

The GBP349 (US$553) M&S Savile Row Inspired suit, designed by Richard James, took seven years to develop and is made from the most sustainable materials available, from the buttons to the lining. Another 2,250 have been ordered for June 2013.

Consumers are also responding to the call for change, with 2.2m used and unwanted pieces of clothing being donated to M&S's Shwopping recycling initiative where they are re-used, resold or recycled by Oxfam.

And a project between M&S and UNICEF has helped more than 700 children in Bangladesh - funded by the money M&S saves by recycling 150m clothes hangers a year.