Protesters occupying a building on Moore Street that is linked to the 1916 Rising are costing the taxpayer €30,000 a day as restoration work is delayed.
Around 15 people remained on scaffolding and in the building last night, vowing to step up their campaign if they do not receive assurances regarding the protection of the entire site.
On Thursday, around 30 activists calling themselves the Save Moore Street from Demolition group gained access to the building that is currently being renovated.
A further 200 demonstrators gathered yesterday outside the site, which is owned by the Government, to protest against redevelopment plans for a number of dwellings on one of Dublin's most iconic streets.
The Government has already bought some buildings, including the location of the last council of war held by the 1916 rebellion leaders.
Work began in November to restore numbers 14 to 17, which are subject to a state preservation order, and get them ready for this year's centenary celebrations. The dwellings are being converted into a new commemorative centre.
However, workers were forced to down tools yesterday after a small group of protesters refused to leave.
A spokesman for the Department of Arts, Heritage and the Gaeltacht said each day the work is delayed will cost the taxpayer around €30,000.
He also warned that the occupation could jeopardise plans to have the buildings ready in time for the centenary celebrations.
However, a spokesman for Save Moore Street from Demolition insisted the whole terrace is of historical significance and demanded that the entire area be protected.
"There's potential for a more embracing redevelopment that would honour this street which is steeped in history. Such a site, with its rich urban fabric and its significance as being part of a battlefield doesn't exist anywhere else in Europe," he said.
The Save No 16 Moore Street group said it was deeply concerned at the actions of the protesters. It also gave its full support for the establishment of a commemorative centre on the site.
Heritage Minister Heather Humphreys said any setback to the work could jeopardise having the buildings ready for the centenary celebrations.
She also expressed her deep "disappointment" that any group would try to delay the work and put the project in doubt.
"The occupation of the building poses risks to the individuals involved and the building itself, which is in a very fragile state," she said.
A statement from her department added that numbers 13, 18 and 19 are not historically significant
The activists were supported by a number of politicians including Sinn Fein chiefs Gerry Adams and Mary Lou McDonald.
Dublin City Council said it welcomed the fact that the restoration works have begun and are being implemented by the Department.
Meanwhile, another group made up of the relatives of those who fought in 1916 are taking a case to the High Court on Monday to try to halt the Moore Street project.