The Wal-Mart owned Asda supermarket chain is now the UK's largest school clothing retailer by both value and volume, according to the latest market share data.

The figures from Taylor Nelson Sofres show that in the highly competitive £900 million a year industry, Marks & Spencer has seen a 6 per cent drop in its share of school clothing sales, according to value.

According to the new information, M&S has a 9.1 per cent share of the sector, while Asda accounts for 12 per cent.

Promotional deals have helped discount chains such as Woolworths and Adams increase their share of the school uniforms market, while more expensive retailers like Bhs and Debenhams have seen their share of the market slide.