A study by Oxfam, independently conducted but with the backing of Marks & Spencer, found a raft of concerns among workers in the retailer’s grocery and footwear supply chains in the UK and India.

Almost 400 people were interviewed for the report at food manufacturing premises in the UK and leather footwear factories in India that supply a range of retailers as well as M&S.

The work was undertaken to improve M&S’s understanding of the issues, which often fail to register in audits because of worker fears, and point to ways forward.