According to a survey conducted by The Grocer, product availability at the UK's six top supermarkets is declining. This is a rising trend in the UK supermarket sector, the investigators suggested, with twice as many products selling out at Tesco, Asda, Sainsbury's, Morrisons, Waitrose and Somerfield now as there were six months ago.

The trend has been blamed on a number of factors - from seasonal weather to the increased emphasis on non-food products. However, Tim Kershaw, the chief executive of food industry consultants Libra Europe, suggested that it was the result of retailers not paying as much attention to traditional shopkeeping.

"The supermarkets have been dealing with many other issues such as reducing waste and carbon emissions, allowing availability and other basic shopkeeping principles to slip down the agenda," he said.

In the last six month, The Grocer found that availability was poorest in Somerfield, with 93.8% of goods on shelves. Morrisons had the best record with 97.8% availability and Asda was second, with 97.6%, followed by Waitrose, 97.5%, and Tesco, 96.7%. Sainsbury's had 95.9% availability.