The public finances recorded a deficit of 1.1 billion euro in January.
That compares with a surplus of more than 700 million at this stage last year when the state coffers were boosted by the part sale of our investment in Bank of Ireland.
Tax revenues in January fell by more than 17 percent at 3.1 billion euro.
But the Department of Finance says this is due to some money being received later than normal because of changes in European payments system.
It said excluding the timing factors tax revenues were up 5% on last year.
