The DUP and UUP are again at loggerheads over the economy.
The DUP's Simon Hamilton has accused Sir Reg Empey's party of being wedded to budget cuts through their alliance with the Conservatives.
But Roy Beggs from the UUP, said DUP leader Peter Robinson had already accepted there would be a reduction.
Finance Minister Sammy Wilson has to find £370m of savings.
Mr Hamilton said: "The behaviour of the UUP is bewildering. Even though they know that a 10% cut in the block grant will have a devastating effect on Northern Ireland, their alliance with the Tory Party means they will not resist those budget cuts. They are wedded to budget cuts.
"The UUP has become the party of cuts. After all their posturing about securing the budgets of departments they control, they do not raise a peep at the prospect of everyone in Northern Ireland losing at the behest of their Tory bosses. They should be ashamed."
The Assembly was debating a DUP motion on the budget.
Mr Beggs said Mr Robinson and the Finance Minister had both accepted cuts would be needed.
"It is really unrealistic to think that nothing is going to fall upon Northern Ireland," he said.
Mr Wilson accused the UUP of getting its facts on the figures wrong.
"There might be a pothole but there isn't a black hole and that pothole was caused by decisions that we as adults took and knew what the consequences were," he added.
© Press Association