Focus Ireland is urging the government to introduce rent controls or increase rent allowance in order to prevent further homelessness in Ireland.
The charity launched its annual campaign to help raise funds for people without a home over the weekend.
The new campaign features radio and outdoor ads.
Recent figures from Focus Ireland show hundreds of families have lost their homes this year and urgent help is needed.
In the first ten months of this year, more then 800 children and their families became homeless. While in Dublin last month alone, 45 families became homeless.
In late October, there were 1,101 people in families - 680 children and their 421 parents - in all types of emergency accommodation, marking the highest level since the housing crisis began.
The charity said this Christmas will be a very challenging time, as demand for its lifeline services grew by 25% last year and the number of families and single people seeking support continues this year.
Sr Stanislaus Kennedy of Focus Ireland says the government needs to keep pace with the recent spike in rents by increasing the rent supplement.