St Vincent de Paul (SVP) is calling on the Government to "declare a national emergency" over the homeless crisis.
It says the Government must act now, as an unprecedented number of families seek emergency accommodation.
The group says the upcoming Papal visit will "bring to the fore the depth of the crisis", and how the use of hotels to meet the needs of homeless families is "entirely inappropriate".
The comments come after a mother and her six children slept in a Dublin Garda Station earlier this week, after having no other accommodation.
Margaret Cash's children, aged from 11-years-old to one-year-old, presented at Tallaght Garda Station on Wednesday | Image: Anthony Flynn
SVP's national president Kieran Stafford says: "It is utterly unacceptable that any child should have to spend a night sleeping in a car or a Garda Station.
"Childhood is short, and at this time of year, children should be enjoying their summer holidays with friends and family.
"No child should have to worry about where they are going to sleep at night."
He says reports of children sleeping in Garda Stations were first heard in May 2017, and "nothing has changed 14 months later."
"It is clear that the current policy has failed."