The Government must commit €2 billion in the Budget to provide 10,000 social housing homes in 2008, according to Focus Ireland.
Launching its Pre-Budget Submission, the homeless charity called for direct action by the Minister for Finance Brian Cowen to provide long-term solutions to prevent homelessness.
Focus Ireland estimates there are 5,000 people who are homeless at any one time in Ireland while there are 43,000 households on social housing waiting lists.
"People living with issues such as mental health or addiction problems can often fall through the gaps in the system," said chief executive Declan Jones.
"Without direct support they often end up in emergency accommodation or can even end up sleeping rough."
The Pre-Budget Submission also contains a range of proposals aimed at providing greater access to early childhood education and healthcare for people on low incomes.
It calls for a well-resourced local authority housing inspection programme to raise the standard of accommodation in the private rented sector.
Existing caps on rent supplements must be raised to include more low-income households, the charity said.
Mr Cowen is due to deliver his Budget to the Dáil on December.
PA