Over a thousand children in the State are now in emergency accommodation, an increase of 22 per cent since January.
Figures published by the Department of the Environment on Thursday show there are 3,081 homeless people, including 1,054 children.
Some 911 of those children are in Dublin, with 143 outside the capital. There are also 1,488 adults officially homeless in Dublin and 947 outside it.
More than half of the families who are homeless are single-parent families.
The Simon Communities in Ireland, a network of eight regional independent units supporting homeless people, said the crisis was deepening.
It noted that from February to March the number of adults in emergency accommodation had increased by 111. The number of children in such accommodation have risen by 116. In total, the number of homeless children has risen by 189 since January - a 22 per cent increase.
Niamh Randall, national spokeswoman for the Simon Communities, said the figures showed the situation was worsening for vulnerable people.
“These latest emergency accommodation figures from March are of grave concern to us and to the people we support across the country every day.
“These figures coupled with the latest rough sleeper count figure in Dublin last week which showed a frightening 151 people had nowhere safe to sleep on one night in April are just unacceptable.”
This included 105 people sleeping rough and 46 people sheltering at the recently established Nite Café.
The Simon Communities said that as Dublin was the only area where an official rough sleeper count takes place, it was difficult to get a countrywide picture.
Figures from Cork Simon Community indicated, however, that rough sleeping in the city had increased seven-fold in between 2011 and 2014.
Ms Randall said it was essential that the Government did not lose sight of the ultimate goal which was to ensure that people who are homeless had access to long-term homes with the right support.
“We needed ongoing action to ensure that hosing is delivered to those who need it most.”
Ms Randall said the biggest challenge at present was access to “appropriate, affordable housing”.
Unless this was urgently addressed, “more people will suffer, more people will end up homeless and the Government will fail to achieve their 2016 target”.
Ms Randall added that emergency accommodation measures announced in December must only be used in the short term. That announcement by the Government followed the death of homeless man Jonathan Corrie in a doorway just yards from Leinster House.
These 291 extra emergency beds in Dublin and Cork must now be replaced by an offer of housing and “not a return to the streets”, Ms Randall said.
Every year the Simon Communities support over 6,000 people and families who experience - or are at risk of - homelessness. In December, it reported a 41 per cent increase in the number of people turning to its services for help over a two-year period.
There are currently 90,000 people in the country on social housing waiting lists.