Most local authorities have not acquired any social or affordable houses under a Government initiative to provide cheaper housing.
Figures obtained by Labour's environment spokesman, Mr Eamon Gilmore, show just 315 houses have been acquired under the Act, and almost 70 per cent of these were acquired by Fingal County Council.
Under original plans 20 per cent of new private housing was to have been set aside for such social housing schemes. Mr Gilmore said nearly 40,000 social and affordable houses would have been built by now if the plans had been kept intact.
"Instead, the Government backed down under pressure from the construction industry, and amended loopholes for builders and developers to enable them to avoid social and affordable housing provisions."
Figures show that just 12 county councils and two city councils acquired any social and affordable houses under the Act. Dublin City Council acquired 11 houses, while Cork City Council did not acquire any.
Department of Environment sources say the modest number is as a result of builders using "stockpiles" of planning permissions granted for land purchased prior to the introduction of the 20 per cent clause in August 1999.
Internal projections compiled by the Department of Environment estimate that around 500 social and affordable houses will be built in 2004, 1,000 in 2005 and 2,000 in 2006.
The Department says Mr Gilmore's figures do not include social and affordable houses which have come on the market dating from a separate 1999 affordable housing initiative.
Construction industry sources, meanwhile, say developers and local authorities are choosing to opt for alternatives, such as financial sums, instead of providing social and affordable houses.