SINN Fein has admitted that one of the key parts of its alternative Budget - an €800m wealth tax - hasn't been costed by the Department of Finance.
It is also accepting the Government's figure of a €3.5bn adjustment for next year, but Sinn Fein is making up the vast majority of funding- €2.76bn - through new taxes.
Despite this, party leader Gerry Adams says his is a “fair tax” , not a “high tax” Budget.
And Pearse Doherty, the party's finance spokesman, admits the figure for the wealth tax hasn't been costed by the Department of Finance like other measures in its alternative Budget.
It is usual practice for opposition parties to have their proposals costed by the department.
Mr Doherty said the department would not cost the measure, which comprises a 1pc tax on wealth over €1m with working farms, business assets, 20pc of the family home and pension pots excluded.