The government says Covid delays led to the Department of Housing not spending around 1.5 billion euro of its capital budget since 2020.
That includes around a billion euro earmarked for social and affordable houses.
New figures show a serious underspend by the Department since 2020 with around a billion euro earmarked for housing not spent
The Government says this is largely driven by the Covid shutdowns of the construction sector
But the trend has continued into this year, with the Department's capital spending about 30% below expectations.
Sinn Féin's Spokesman Eoin O'Broin says it's about red tape.
"The problem is that there are too many beauraucrats getting in the way of project delivery. What we cannot have is the officials in the Customs House micromanaging every single aspect of every single housing project. That is the responsibility of local authorities."
That's something Fine Gael senator Barry Ward denies.
"Eoin described last years delivery of social housing as being meagre. It is the greatest delivery of social housing since I was born. "
The one billion euro not spent is estimated to be the equivalent of 4,000 homes