It says social welfare recipients will also be worse off in real terms in the coming year, although they were the only net beneficiaries from the measures.
CORI says the working poor - who constitute one third of houses at risk of poverty and who were outside the tax net this year - will pay the new 1% levy on every euro they earn.
It predicts an increase in child poverty due to the failure to boost Child Benefit, the value of which will shrink in real terms by 2.5% next year.
It says that even allowing for changes to the Family Income Supplement many working poor households will see their standard of living fall.
The Government was commended for funding 200 additional primary care teams, maintaining social housing output and for standard rating health expenses relief.
But it criticises the allocation of just 55c a week in welfare payments to compensate for food price inflation, which is well ahead of the standard rate of inflation.
It says this hits poor people disproportionately because they spend a much larger slice off their income than others feeding themselves.
