The organisation's latest Distributive Trades Survey reveals 48 per cent of retailers said like-for-like sales for the first two weeks of September were down on last year.

But 21 per cent said they had seen an increase.

The balance of 27 per cent marks a third month of falling sales, but is an improvement on the CBI survey's record low of minus 46 per cent in August.

The organisation predicted a balance of minus 30 per cent for October.

CBI South East Regional director Malcolm Hyde said: 'Shoppers are increasingly focusing on price as the economy continues to slow and household budgets get tighter. There has been a marked migration to the value end of the market, and many have cut back on luxuries.

'Retailers of big-ticket items like furniture and white goods, which are closely tied to the ailing housing market, continue to suffer. Supermarkets have fared much better in these difficult times, particularly those that have realigned their range to match the price conscious.'

Looking at individual sectors, the supermarkets continued to weather the economic slowdown, and a balance of 37 per cent of grocers reported like-for-like sales growth.

All other sectors saw a fall in sales – especially sharp in those sectors linked to the housing market.

Wholesalers fared better expected, and only a balance of four per cent of firms said that sales volumes were down over the year to September.

Clothing, textiles and footwear wholesalers reported sales growth on a year ago, while builders' merchants had a third consecutive difficult month.

Over the year to September, motor traders saw sales volumes fall heavily, a balance of minus 78 per cent, for the fourth month running, and October is set to be similar at minus 86 per cent.

The survey, which first began in 1983, polled 149 firms.