Provisional figures show that consumer spending weakened in December, with the volume of retail sales dropping 1.1% from November. The monthly drop was the biggest since January last year and followed two months of small increases.
The Central Statistics Office said the fall was even bigger when motor sales - which were boosted by the scrappage scheme last year - were excluded. Sales excluding the motor sector fell by 2.5% from November.
The CSO said sales volumes were down 3.1% compared with December 2009, again the worst figure since January last year.
The CSO also gave early estimates for 2010 as a whole, which showed that the volume of retail sales increased by 0.9% compared with 2009, though there was a 1.8% fall when motor sales were excluded.
Read the full CSO report here
A breakdown showed that fuel sales slumped by 14% in December, as motorists cut down their journeys due to severe weather, while furniture sales were down 8%. Sales in the hardware, paints and glass category were down 1.6%, but bar sales picked up by 2.1%, though they are still down almost 10% over 12 months.
NIB economist Ronnie O'Toole said most of the decline in sales was due to the weather, and the January figures were likely to show a one-off improvement. But he warned that 2011 was likely to be another difficult year for consumer spending.
The value of sales, which takes prices into account, fell by 0.9% from November, giving an annual drop of 4.1%.