Half of its spring-summer range has been made according to the new standards, which were prompted by a customer survey that showed more than half think sustainability is a key concern when buying jeans.

The retailer claims it sells one in 10 pairs of jeans to customers across the UK, the new standards are part of its “wider approach to sustainable clothing”. 

Through the pandemic, it has seen a continued demand for denim – in particular its bestselling jegging, of which its sells two pairs every minute.

It said its work with suppliers and Jeanologia means M&S jeans will be made with 86% less water compared to the industry standard for denim finishing and it is switching standard indigo dyes with “cleaner alternatives” that require less water and fewer chemicals.

Monique Leeuwenburgh, head of product technology for M&S Clothing & Home, said: “Denim is a wardrobe staple for our customers – but we know now more than ever they want style where sustainability is built in as standard. 

“By taking collaborative action with our denim suppliers, we can give our customers the confidence that every pair of M&S jeans they buy for the family are not only stylish, great quality and fantastic value – but have been responsibly made too. Our new spring/summer denim campaign brings that value promise to life across our digital channels.”

The retailer recently became one of the first companies to sign the Call to Action to ensure that its supply chains are not linked to the human rights abuses in the Xinjiang region. Last month, M&S also asked Oxfam to conduct an analysis of its supply chains in the UK and India to better understand the true worker experience.