Figures for like-for-like sales - which exclude new floorspace - showed a 4.6 per cent fall, the worst since the BRC started compiling the data in 1994. The BRC said there was no inflationary pressure from the retail sector as consumers continued to look for lower prices.
Separate data showed that manufacturers are finding it impossible to pass on rising raw material costs to retailers.
Ann Robinson, BRC director-general, said: "These figures provide hard evidence that there is not yet a recovery in the retail sector. Interest- rate cuts seem to have had little impact."
Pamela Webber, the BRC's economist, said the 4 to 5 per cent growth in average earnings and the rise in the number of people in work had not fed through to increased spending. She said that the reported recovery in housing had failed to feed through to increased sales of furniture or carpets.
However, the BRC admitted the figures were depressed by Easter falling in April this year but in March in 1998. Average monthly growth for the quarter to April is running at 3.6 per cent.
The benign picture for inflation was supported by figures from the Office for National Statistics showing prices of goods leaving the factory gates unchanged in April.
Output prices rose by 0.7 per cent last month, well above a forecast 0.2 per cent rise, due to a combination of Budget excise duties and higher oil prices. But excluding food, beverages, tobacco and petrol, the core figure was flat in April and showed an annual fall of 0.6 per cent.