A national campaign focusing on making housing a legal right has been launched by the Raise the Roof group.
The campaign will include a national petition and a series of regional rallies culminating in a national protest, according to representatives.
Speaking in Dublin's Mansion House to announce a conference for 30 January, ICTU President Sheila Nunan said this week marks the centenary of the first Dáil, which demanded that private property rights be subordinated to public welfare.
"Today's housing emergency graphically illustrates the failure to do so" she said.
She pointed out that all the political parties, except Fine Gael, passed a Dáil motion last October to make housing a constitutional right.
The Raise the Roof campaign represents trade unions, political parties, student unions and homeless groups.
Union of Students in Ireland Vice President Colm O'Halloran said students starting college were in a panic about accommodation.
He said students are being forced to pay €1,000 a month for purpose-built student accommodation because they could not find anything else.