The cost of living for households could rise by more that €1,300 a year in the event of a hard Brexit, according to a leading social justice charity.
Extern provides supports to 20,000 vulnerable adults and young people on an all-island basis.
It said they will be seriously impacted by Brexit, yet the British and Irish governments are sitting on their hands when it comes to addressing issue.
Charlie Mack, Chief Executive of Extern, said the tourism and business sectors have seen contingency funds put in place, but charities have been forgotten about.
He said: "The lack of uncertainty of funding and certainly the lack of care that both the Westminister and Irish governments have shown in relation to the third sector, no commitment, no credible plan from either government about how to help vulnerable young people and families."