Consumer confidence fell to its lowest level ever in December 2012.
The index, measured by KBC Bank Ireland and the ESRI, shows consumer spending fell from 63.8 in November to 49.8 in December.
The drop is one of the largest on record in the 17-year history of the records.
Austin Hughes of KBC Bank said the Budget played a big part in the decline.
"We've seen in the last couple of years that the Budget tends to have an exaggerated effect on consumer sentiment," he said.
"The hope is that we'll see some modest recovery in the months ahead. Consumers were much more nervous about their own household finances, and that's perfectly understandable after the range of budget measures."