Opposition parties have called on the Government to step in after it was revealed that five social housing regeneration projects around Dublin city are likely to be delayed or scrapped.

It follows confirmation from Dublin City Council that a developer involved in the public-private partnership has pulled out.

Construction firm Michael McNamara & Co told the council about its decision not to proceed with the developments yesterday.

The company said the projects were now not viable because of the tough residential housing market and the costs of recent changes to building regulations involving increased apartment sizes and better energy efficiency.

The schemes affected include a €265m regeneration project at St Michael's estate, Inchicore, that has been planned for seven years.

Fine Gael described the collapse of the deal as a blow to the most vulnerable in Dublin society and called on the council and the Government to take immediate action.

The Labour Party has also called on Dublin City Council to make alternative arrangements for the construction of 138 units at St Michael's estate, which already have planning permission.

On RTÉ Radio's Morning Ireland, Chairman of the St Michael's Regeneration Scheme Finbarr Flood said the project would not be abandoned.