Supermarket home shopping web sites were accused yesterday of failing to deliver what they promised.

A snapshot survey found problems with almost all the web-based services, including items either missing or others not ordered and deliveries not arriving on time.

Ordering from a supermarket web site is promoted as the quick and easy way of buying groceries.

But the survey by trade magazine The Grocer found numerous problems when it attempted to buy the same 33 products from web sites run by Sainsbury's, Tesco, Asda, Iceland, Waitrose and Ocado.

It took one hour and 20 minutes to order the 33 items from Sainsbury's but although the company promised to deliver within 24 hours it arrived three hours late.