The Government is being urged to consider the current homeless problem in Dublin as a "natural disaster".
Dublin City Council is facing an €18.5m shortfall in the projected necessary funding.
Councillors sought €55m from the Department of the Environment, but only €37m was allocated, although negotiations are ongoing.
Mike Allen of Focus Ireland says extra money is needed to deal with the scale of the problem brought about by the recession.
Mr Allen said: "This sort of business of a stand-off between Dublin City Council and the Department of the Environment happens every year, but it doesn't happen over €18m, it usually happens over €1m or €2m.
"The scale of this is extraordinary.
"If we are going to have a coherent response to this, this has to be funded separately, you can't fund it out of the same pocket."