The number of people homeless increased significantly in January just weeks after the figures dropped below 10,000.
Statistics published by the Department of Housing on Thursday showed the number of people in emergency accommodation stood at 10,271 in the week January 20th and 26th, up from 9,731 the previous month, a rise of 540 people.
The number of children increased by 152 to 3,574 for the week.
In January, 2019 there were 9,987 people in emergency accommodation, including 3,624 children.
With government-formation talks under way, Focus Ireland has used the latest data to repeat calls for homelessness to remain central to the next administration's agenda.
"It was clear in the recent election that voters from all parts of the country want this homelessness and housing crisis to be ended," said its chief executive Pat Dennigan.
“While I understand delicate talks of this nature can take time, the nearly 4,000 children homeless don’t have time. For every extra day our TDs negotiate a government formation, three families become homeless every day.”
Mr Dennigan appealed for an end to “party politics” and for a focus on remedying the ongoing problem.
Focus Ireland continues to criticise a "primary response" of building more homeless emergency accommodation rather than more homes.
The Simon Communities, meanwhile, note that the latest statistics also show 4,400 single adults in emergency accommodation, an overall increase of 7.2 per cent since January 2019, and 1,611 families, a reduction of just three in the same period.
"While a January increase in emergency accommodation numbers is not unexpected following seasonal declines over Christmas, it shows that there is still a mammoth amount of work to be done to turn the corner," said spokesman Wayne Stanley.
He said there has been a 267 per cent increase in homelessness since January 2015 and also renewed calls for a fast political solution.
“In the meantime, the Simon Communities continue to work with local authorities, government departments and other NGOs to try and alleviate the worst effects of this crisis,” he said.
“The three months of decline of families in emergency accommodation in the Dublin Region at the end of 2019 was an encouraging sign that these combined efforts can have an impact.”