The volume of retail sales fell 9.9 per cent in June compared with the same month in 2008, according to new figures from the Central Statistics Office.
The value of sales was also down, decreasing 15.1 per cent on June last year.
However, there was a slight increase from the previous month, with volume of sales rising 2.2 per cent and value up 1.2 per cent compared to May 2009.
The worst of the fall was felt by the motor sector, which has seen a 30.3 per cent drop in sales volume year on year. Household equipment and bars fell 16.1 per cent and 12.7 per cent respectively.
Sales of clothing, footwear and textiles fell 4.2 per cent during the month, while non-specialised stores - including supermarkets - saw a decline of 5.2 per cent.
Excluding the troubled motor trade, volume of retail sales decreased 5.5 per cent compared to the previous year, with the monthly change showing a rise of 2 per cent.
However, it wasn't all bad news for the retail sector, with a 10.2 per cent increase in sales of pharmaceutical, medical and cosmetic articles, and a 1 per cent rise in sales of fuel.
On a quarterly basis, sales volume fell 13.9 per cent compared to the same period a year earlier. Sales value fell 18.1 per cent.
Taking the motor trade out of the figures saw the decline in volume ease to 7.6 per cent, while value was 12.1 per cent down.
