The Irish Housing Network, backed by a number of musicians and celebrities, occupied the vacant former Department of Social Protection offices at Apollo House in Dublin city centre for use as a shelter for rough sleepers on Thursday night.
Oscar-winning singer-songwriter Glen Hansard of The Frames and fellow singer-songwriter Damian Dempsey are among those who joined the occupation.
Mr Hansard acknowledged last night that the sit-in was illegal, but said it was a necessary act of civil disobedience.
Speaking on The Late Late Show, he said Apollo House was effectively owned by the taxpayers.
“That is essentially our building. We are just going to take it for a few months,” he said. “What we are trying to do is get a national conversation started. This should be a national emergency.
“Not since the Famine have families been homeless like they are right now. It is really, really difficult.”
Film director Jim Sheridan, actor John Connors, and musicians Hozier, and Christy Moore are among the other well-known figures supporting the campaign, either in person or through social media messages.
However, the Department of Housing disputed the need to take over the property, saying an additional 210 beds had been provided for rough sleepers this winter and there was emergency accommodation available for anyone who wanted it.
The receivers for the property, Mazars, meanwhile said the building was not suitable for living accommodation and the occupation presented a health and safety and insurance risk for which they could not take responsibility.
Mazars said the campaigners were trespassing and asked them to leave with immediate effect. “In the circumstances we have no option but to refer the matter to our legal advisers to pursue the appropriate course of action,” they said.
The Irish Housing Network and the Home Sweet Home campaign said they had no plans to leave and were last night seeking volunteers with first aid training, CPR skills or experience working in homeless or community services to get in touch.
They said many other volunteers offering general help had already been in contact and would be responded to over the coming days.
Sinn Féin president Gerry Adams, who visited the occupation yesterday morning, applauded the campaign.
“It is an indication of the extent of the homelessness crisis that activists have been pushed to occupy a building that’s been lying idle for six years in order to provide some form of refuge for those forced to sleep on our streets,” he said.
In the Dáil, Fianna Fáil TD Anne Rabbitte urged Housing Minister Simon Coveney to facilitate the occupation if it was needed over Christmas.