The grandson of James Connolly has expressed concern at the condition of No 16 Moore Street, the final headquarters of the provisional government during the Easter Rising in 1916.
John Connolly yesterday described the neglect of the house as "shameful" and said that, despite commitments to preserve the building, it was falling apart before his very eyes.
Mr Connolly, who lives in Bray, Co Wicklow, and who owns a welding and engineering company, said he has observed that the building is missing a substantial number of roof slates, which he fears is leaving the interior exposed to the elements.
During Easter Week 1916 the house was where the wounded James Connolly, Pádraig Pearse and others, including Seán MacDermott, Thomas Clarke and Joseph Plunkett, made the decision to surrender on Easter Saturday.
Two years ago a high-profile campaign was started by the National Graves Association, the Academy for Heritage, historian Tim Pat Coogan and others including lord mayor Dermot Lacey, to save the building after it was earmarked for demolition.
Shortly after Dublin City Council agreed that the building be "retained and incorporated into the planned regeneration" of the area and be developed as a public information and education centre.
The present Dublin City Development Plan proposes that No 16 Moore Street be converted into a museum, which would be owned, run and administered by Dublin City Council.
"It is an objective of Dublin City Council to preserve No 16 Moore Street as a commemorative centre marking the events of 1916", according to the plan.
The building is in the middle of the site originally earmarked for redevelopment by the Carlton Group as part of the O'Connell Street area regeneration programme.
However, the plan to develop the former Carlton Cinema through to Moore Street failed to materialise, and the scheme and the sites are locked in legal wrangles.
In December 2001, Dublin City Council initiated compulsory purchase proceedings, but a judgment by the High Court in favour of the council is now being appealed to the Supreme Court by one of the former partners of the Carlton Group.
Last May in a Dáil reply, Minister for the Environment Dick Roche said that, despite the provisions made by Dublin City Council, No 16 Moore Street "is not currently included in Dublin City Council's record of protected structures".
Chairman of the antiquities and national monuments committee of An Taisce Dr Mark Clinton said yesterday that the situation was "simply not good enough".
"It does not matter that a local authority may have good intentions if they are incapable for whatever local reason," he said. "If a building is of such national significance then surely it must be a priority for a national heritage protection agency to step in."
A spokesperson for Dublin City Council said yesterday although the building is not listed to be protected for its architecutre, it is listed to be preserved arising from its historical significance.
A public meeting on the future of the building has been convened by An Taisce for 3pm next Sunday at Tailors Hall, close to Christ Church.