Social justice campaigner Fr Peter McVerry has warned of a "tsunami of homelessness" over the housing shortage in Ireland.
He said that in his 40 years working with homeless people in Dublin, the problem was never as pronounced as it is now.
Speaking on RTÉ's Sunday with Miriam, he said his charity – The Peter McVerry Trust – is having to turn people away for the first time due to a lack of capacity.
"In all the years I have been working with homeless people, it has never been so bad. We are, even I would say, beyond crisis at this stage.
"There are six new people becoming homeless every day and that's the official figures. It may be more than that".
Fr McVerry said with up to 35,000 home repossessions feared over the next few years, the rise in homelessness could bring down the Government.
He said many people who would not be considered "ordinary homeless people" may lose their homes through repossession leaving thousands of families looking for accommodation.
He said: "There are also 40,000 buy-to-let mortgages in arrears ... there is a dam at the end of the river, and this torrent of water is coming down, and there's no way out".
"Ultimately, because of the changing nature of homelessness, these are ordinary people who will vote, and their families will vote, I think this whole issue of housing and homelessness could bring this Government down", he added.
Fr McVerry said the problem was growing as the traditional exits from homelessness - social housing and the private rental market - were no longer open to people.
"There is a dearth of social housing. In the cities, and in Dublin in particular, the private rental sector is out of reach for homeless people because the rents are escalating, they are going through the roof".
"The demand for rented accommodation far exceeds supply, and not only can homeless people not get into rented accommodation but people already in rented accommodation are losing it. So, the people in rented accommodation are losing their accommodation and becoming homeless", he added.
Fr McVerry called on the Government to purchase 1,500 houses and apartments in order to ease the crisis.
He said it would be far cheaper for the Government to support homeless people in accommodation rather than putting them into a hostel or shelter.
Minister for Housing Jan O'Sullivan said she is working with the Department of Social Protection to allow some flexibility with regards the rent supplement for people who are in danger of becoming homeless.
Speaking on RTÉ's This Week, she said her department was also investigating the possibility of converting vacant properties - such as former garda stations - into affordable accommodation.