Dublin Simon has warned of a €1 million shortfall in funding as it faces what it calls a "daunting" challenge dealing with the needs of increasing numbers of homeless people.
The charity says that government funding for homeless health services has plummeted by 54% per person over the past six years.
CEO Sam McGuinness said "health spending in homeless services stagnated while homeless numbers accelerated. It is not even close to meeting the needs of the sector".
The charity which provides detox and healthcare as well as outreach services and emergency accommodation says it saved over 1,000 people from homelessness last year.