SIPTU want the situation declared a national emergency
A mass protest is planned for Dublin city on Saturday to highlight the need for government action to end the housing crisis.
Trade unions SIPTU and IMPACT are both supporting the rally, which will begin at 2.00pm at the Custom House.
It is being organised by the National Homeless and Housing Coalition, and will end with a rally outside the GPO on O'Connell Street.
IMPACT says it has written to its branches urging them to support the protest.
Last week, the union's biennial delegate conference reasserted the their support for urgent solutions to the homelessness crisis - including the regulation of rents through an indexation system similar to those adopted in other European countries.
IMPACT official Joe O'Connor said the protest would put pressure on the new Government to implement urgent measures to deal with the homelessness and housing crisis.
SIPTU national campaigns and equality organiser, Karan O'Loughlin, says they want it declared a national emergency.
"When you declare it as an emergency situation, that frees the Government to act faster", she told Newstalk Breakfast.
"They have plans in the system for 35,000 housing units over the next five years - that's still inadequate in our view".
"If you were to really, really grapple with the problem it would take a whole raft of other measures - you'd need to be building about 10,000 units every year for the next nine or ten years".
"The problem is so big, and at such a crisis level that unfortunetly even though (Minister Simon Coveney's) efforts are well-meant, it's just not going to be enough".