The latest Exchequer figures show tax receipts exceeded expectations by over €1.2 billion in the first ten months of the year.
The figures show an overall Exchequer deficit of €1.29 billion in the despite a the rise in tax revenues.
This compares to a deficit of €1.202 billion for the same period last year.
Tax revenues rose from €27.095 billion to €29.421 billion as the Revenue Commissioners secured more tax evasion settlements.
Stamp duties, excise and VAT were all ahead of projections, but Corporation Tax receipts were €200 million lower than targeted.
Total current receipts were €30,720 million compared to €28,577 million last year.
But Fine Gael's finance spokesman Richard Bruton said: "The figures reveal that capital spending has remained almost 15 per cent behind projection, which means money is not being spent on some key infrastructure projects."
Mr Bruton said: "State spending on capital projects is now €514 million short of the projection for 2005, casting serious doubts on the Government's ability to deliver capital projects effectively."
Labour's finance spokeswoman Joan Burton said the figures "poured further scorn, if it were needed, on the Government's Transport Plan"
Ms Burton said: "The target for Exchequer capital spend for the first ten months of this year was set at €3.6 billion but the outturn was only €3.1 billion."
"How can the Government credibly claim to have a €35 billion plan, when they can't spend €3.6 billion," she said.
"In fact, compared to the first ten months of 2004, capital spending has increased by only €50 million, or a mere 1.7 per cent," she said.