The UK's biggest clothing retailer Marks & Spencer hopes to recycle up to 350 million garments a year under a new scheme that calls on its customers to donate one item of clothing every time they buy another. Executive director of marketing, Steven Sharp, spoke to Petah Marian about the new Shwopping initiative, launched today (26 April) in partnership with Oxfam.

The retailer says it will accept unwanted clothing from any brand, all year round, with the garments then being resold, reused or recycled through Oxfam. The aim is to recycle as many clothes as it sells - 350m pieces a year.

Sharp says the plan grew out of a series of one-day wardrobe clearances M&S has been organising with Oxfam, which achieved "real traction" after hundreds of thousands of garments were donated to the retailer each time.

The programme was spurred by a challenged from eco-campaigner Jonathon Porritt, who said: "You've been doing a brilliant job, every one thinks you're marvellous, companies come and look at you and try and emulate what you're doing, but what you really need to do now is leverage the power of your trust, of the 21m people to get something really important done."

Sharp is hoping the programme will lead to a change in consumer behaviour, citing the shift in how people deal with plastic bottles as an example.

"You wouldn't dream of throwing a bottle in an ordinary bin any more, if you can create the [same] habit with shopping, then we can create real change, but with very little effort."

The programme will see the retailer re-use the empty lorries that leave its stores after clothing deliveries. These will then take second-hand clothing to Oxfam's "facilitation" department, with items sorted to be resold in Oxfam's stores, or stripped back to fibres and remade - like the company's cashmere coat collection launched last year - or incinerated.

"Only 1% gets incinerated," emphasises Sharp, "and even the heat generated gets turned into energy."

While Sharp admits that the recession has seen consumers focus more on value than sustainability, he emphasises that economic problems are eventually "going to go away, but the problems of the world are not".

Instead, the "thrifty" mindset bought about by the recession, Sharp believes will only help M&S's cause. "There's an empathy towards being careful about things, and if you can't use something, someone else can."

M&S last week booked a decline in first-quarter clothing sales after running short of stock in a number of key items - although Sharp emphasises this happens to every fashion retailer at some point.

"The interesting thing about fashion is that it's half art and half science. We have buying and merchandising teams, and with the span of products we've got, and the span of sub-brands we've got, from time to time, with the best will in the world, the best systems in the world, you over-play something, you under-play something.

"Every business does it, we're reinventing, recreating, it's disappointing, but it's not life threatening, we'll get through it."