Tax revenues for this year are significantly lower than the Government had predicted, according to exchequer figures released this afternoon.
Receipts are up around 1% compared to the same period last year, but the Government had predicted an 8.6% increase.
The exchequer figures also show a surplus of €952m in the year up to the end of August, less than one-third of what the Government had expected.
Public spending, meanwhile, rose at an annual rate of 18.9%, compared to the budget forecast of 14.4%.
The Opposition said the figures could lead to further Government cutbacks.
Fine Gael accused the Fianna Fail-Progressive Democrats coalition of misrepresenting the true cost of commitments they were entering into, while the Labour Party accused Finance Minister Charlie McCreevy of mismanaging the economy.