Serious concerns have been raised over the €2.2bn that went unspent across housing, health, and other areas last year.
At the end of December, exchequer spending stood at €87.54bn, continuing the trend of historically high spending on public services.
Despite this, total capital and current spending was €1.38bn below forecast.
But the total overall spend incorporates €820m of capital funding which will be carried over to 2022, meaning actual in-year spending was €2.2bn below expectation.
Independent TD Sean Canney has said he is "concerned" by the significant underspending on vital infrastructure, which he warned will result in project targets being missed.
“I am concerned at the underspend in housing, transport, and health infrastructure," he said.
Mr Canney, who is a member of the Budgetary Oversight Committee, is now calling on the Government to use the underspend to target projects that are shovel ready for construction.
He wants the unspent money reallocated to departments that can spend money and deliver projects quickly for the benefit of communities.
“There are no shortage of projects and we need to keep providing the necessary infrastructure," he said.
"A good example in transport is Phase 2 of the Western Rail Corridor. This project can commence construction within a matter of months as it does not require planning or any other statutory consents.”
A maximum of 10% of unspent capital allocations can be brought over to the following fiscal year, subject to approval. This year, a record high carryover will be dispersed across 19 areas with housing, local government, and heritage carrying over around €276m, transport €161m, and health €104m.
In total, an estimated €795m in current spending and €580m in capital spending was unspent at the end of the year, and therefore surrendered to the exchequer.
End-of-year expenditure on social protection was €30,274m, while spending on health, including the HSE, was €21,761m.
Cumulative tax receipts to the end of December were the highest ever recorded at €68,410m. This is €6,465m (or 10.4%) better than expected and €11,254m (or 19.7%) greater than last year.
Corporation tax receipts to the end of the year were €3,269m ahead of what was targeted. With receipts of €15,324m for 2021, this is the largest amount ever received in corporation tax in a given year.
Other significant revenue streams also performed better than expected. Income tax was 11.2% greater than expected for the month and Vat was also 21.6% above what was profiled.
These figures, together with lower than expected expenditure, mean that the projected general Government deficit has improved from a projection of €13.25bn, as outlined in Budget 2022, to just under €9bn.