The number of social homes built so far this year is less than half the government's targets.
New figures from the Department of Housing show 2,369 social housing units have been completed to the end of September.
That's 80% higher than the same time last year.
Just under 5,000 homes were under construction at the end of the third quarter.
Housing Minister Eoghan Murphy says more social housing should be delivered by the end of the year.
However, Labour's Housing Spokesperson Jan O'Sullivan is calling on the Minister for Housing to explain the discrepancy between the target and the actual number.
"The Minister for Housing has to explain the figures released today that show only 48% of the social houses that were to be built this year have been delivered by the end of the third quarter.
"There is no realistic prospect of the full target of social housing being delivered by the end of the year. The Minister must explain to opposition parties, and the country, why less than half of the homes he committed to be built this year have been delivered so far.
"Given the scale of the crisis in front of us now, this really isn't acceptable.