New figures showing nearly 10,000 people are homeless are "not worth the paper they are written on", according to experts in the area.
The Inner City Helping Homeless (ICHH) group and the Simon Community have both questioned the validity of figures which show a slight increase in people requiring emergency accommodation during October.
Department of Housing officials reported that there are now 9,724 people, including 3,275 children, relying on the State for accommodation. This is up 15pc on this time last year.
Housing Minister Eoghan Murphy said a month-on-month jump of 26 people can be partly explained "by new beds being provided to help take people from rough sleeping and into our supported services".
But chief executive of ICHH Anthony Flynn was hugely critical of the way the figures are calculated.
"The minister and the Department of Housing are being completely disingenuous in relation to the homeless figures," he said.
"The process of registering as homeless is becoming more complicated and in one case we saw it take nearly two weeks for someone to register as homeless and avail of services."
Mr Flynn intends to write to Taoiseach Leo Varadkar asking that the Central Statistics Office immediately takes over the compilation of figures, as at present "they are not worth the paper they are written on".
Likewise, the Simon Community said the rationale for recent re-categorisation of some homeless cases "remains unclear".
The charity pointed to spiralling rents as a key factor.
"Without an accessible private rental sector or social housing, people have nowhere to go if they cannot afford to rent," said Niamh Randall, spokesperson for the Simon Community.
While much of the focus has been on Dublin, Ms Randall said the number of people her organisation is working with all around the country are "increasing dramatically".