Home Sweet Home says it's looking to fund a "sustainable project" with money left over from it's Apollo House campaign.
It raised €190,000 when a group of volunteers along with homeless people occupied an unused building on Tara Street before Christmas.
€61,000 was spent on security, utilities and heating Apollo House leaving it with €129,000 in public donations.
Lord Mayor Brendan Carr wants the group to give to homeless charities.
He said: "Rather than letting this money lie in an account it should be immediately put to use assisting people in housing need. This was the reason it was given to the Home Sweet Home campaign and to not put it to such a use immediately, I believe, is an abuse of peoples' wishes to ensure the dire housing crisis in our city is effectively dealt with."
Home Sweet Home Spokesperson Freda Hughes says they are looking at different options.
She said:We're working at the moment with other grassroots groups dealing specifically with homelessness and the housing crisis to look at how best we can put the money into sustainable projects."
She added: "We're also taking lots of ideas and proposals from volunteers that were involved."