Retail sales decreased by 2.5 per cent last month, according to figures from the Central Statistics Office (CSO).

However, the figures show sales have increased by 7.4 per cent on an annual basis.

If motor sales are excluded, there was a monthly decrease of 2 per cent in the volume of retail sales and a 5.5 per cent increase in the annual figure.

The sectors with the largest month-on-month volume increases were books, newspapers and stationery, which rose 7.6 per cent, and electrical goods which rose 3.2 per cent.

The sectors with the largest monthly decreases were food beverages and tobacco (down 4.8 per cent), department stores (down 3.9 per cent) and hardware, paints and glass (down 3.5 per cent).

There was a decrease of 2.6 per cent in the value of retail sales last month, when compared with April 2015 and there was an annual increase of 4.3 per cent when compared with May 2014.

Retail Excellence Ireland said that the statistics demonstrate that the retail industry is still aggressively discounting to attract footfall and secure sales.

"While today's retail sales data are positive, it is disappointing that sales value still lags behind sales volume on a year-on-year basis. The annual value increase of 2.5 per cent is modest and is somewhat disappointing when contrasted with the annual volume increase of 5.5 per cent —when Motor Trades are excluded," REI chief executive David Fitzsimons said.

Goodbody stockbrokers said it was “unsurprising” to see some of the strength in retail sales ease in May, following the surge in volumes seen in April.

"We expect consumer spending to increase by 2.6 per cent this year, supported by positive trends in the labour market and the wider economy, although the recent strength in retail sales poses an upside risk to this," Goodbody economist Juliet Tennent said.