World Homeless Day will be marked by sleep-outs around the country this tonight - including outside Leinster House in Dublin.
Activists are urging the Government to declare a national emergency on the issue.
Organisers, who will be sleeping outside Leinster House from 8pm until 8am, say they were moved to take action following the death of Jonathon Corrie near Leinster House last year.
One of those behind the event, Darren Bradley, says politicians need to wake up to the issue:
Other sleep-outs, organised by March For The Homeless, will be taking place in Waterford, Mayo, Tipperary, Cork, Cavan, Limerick and Galway tonight.
Members of March for the Homeless Massachusetts in the US will be holding a candlelight vigil in the city of Lynn.
Recent figures have shown that the number of individuals in emergency accommodation in Dublin has increased to 2,298, with the number of homeless families having jumped by 106% in the last 12 months.
Sinn Féin TD Dessie Ellis this morning said, "there is time for this government to change tack. Next week's budget is an excellent opportunity to prioritise measures which can end the homelessness emergency and start to tackle the shortage of affordable housing but it requires decisive and substantial action."
