Up to 24% of the Irish population is at risk of poverty, according to a new economic report by TASC.
The economic report also found that 27% of Irish children are at risk of poverty.
It shows working and lower-middle-class people are struggling more because of low pay and poor labour protections.
The top 10% of earners in Ireland receive almost 25%of the national income, the report shows.
TASC is warning inequality is being made worse by the high cost of living and a lack of universal access to public services like health, childcare and housing.
The report's author, Dr Robert Sweeney, said there are a number of reasons why people are on the brink of poverty.
Dr Sweeney said: "The fact that we have quite low labour force participation, in part due to our low universal public provision in services and also the fact that we have quite high levels of low pay, these factors tie in to Ireland's high level of risk of poverty and also Ireland's high level of deprivation."