Following a visit to the buildings, James Connolly Heron said the houses are falling down and in worse shape than when a protection order was issued for them in 2007.
He said Heritage Minister Jimmy Deenihan needs to intervene and block a planning application that has been proposed for a large quarter between Moore St and the GPO.
He said the developer behind this application had not preserved or protected what is supposed to be a national monument.
“All protected buildings and structures that form part of the national monument are dilapidated and endangered. The condition of the very room where my great-grandfather and five other leaders of the Rising spent their last hours of freedom before their execution is beyond belief.
“This is where the momentous decision to surrender was taken. This historic room is in a ruinous condition, with water ingress, rotting floors, and decayed plaster work. The intact walls are covered in graffiti. Those responsible for its preservation and upkeep should hang their heads in shame,” he said.
The site is mired in controversy as Mr Deenihan considers planning proposals to demolish part of the site.
At this month’s meeting of Dublin City Council, a special report was adopted that looked at the need to protect the houses.
This recommended that it intervene in Nama-backed plans to redevelop the area. It said Nama and the development company with control of the area, Chartered Lands, should reconsider proposals for a mixed use development.
It also said Mr Deenihan should withhold consent for any construction work on the buildings.
The review group was established last year after revelations regarding a decision by the council to facilitate the acquisition of neighbouring properties off O’Connell St by Chartered Lands.
This was done without the knowledge or consent of councillors.
The committee said with the centenary of the 1916 Rising three years away, there needed to be certainty as to the future of the area, independent of the fate of a more comprehensive development scheme.
“There is no indication that works will commence on the overall develop-ment in the near future. It is possible that the large scale development which has planning permission may never take place in its current form,” the committee said.