Dublin City Council has said the Government has left it €18m short in tackling homelessness.
Assistant Chief Executive Richard Brady told councillors this evening that the deficit is "serious" and could affect services.
The council requested funding of over €55m last April but have been informed by the Department of the Environment that it will get just €37m for this year.
Mr Brady said the council as the lead authority in the Dublin area had plans to build 150 residential units, were providing 146 units to homeless families and had let out 181 of its own units.
"But the numbers are increasing at such a rate that these actions will not see a downturn in relation to the number of homeless families" he said.
The council's monthly meeting heard that 66 more families presented as homeless in May and another 65 in June.
There were 3,307 people in homeless accommodation in Dublin in June including 1,122 children.
Mr Brady said the council is continuing to have "serious negotiations" with the Department of the Environment.
Many councillors expressed shock at the report and criticised Minister Alan Kelly.The meeting also heard that a programme to refurbish empty units had run out of funding.
Dublin's Lord Mayor Críona Ní Dhálaigh said she was calling for a round table meeting with the Government and other interested parties as a matter of urgency.
Ms Ní Dhálaigh said minister Kelly has agreed to meet the city council's corporate policy group, which includes chairs of special purpose committees, group leaders and council officials.
In a statement, the Department of the Environment said: "The Department is aware of Dublin City Council's projection of expenditure in respect of homelessness and we are in discussions with them in this regard".